Exam 2 Flashcards

Sexual Reproduction

When two organisms are needed to produce an offspring. One provides the sperm and the other provides the egg. After the egg is fertilized it is called a zygote.

Genome

A cell's endowment of DNA. Prokaryotic cells may be made with as little as one strand of DNA while eukaryotic genomes usually consist of multiple DNA molecules.

Chromosomes

The location where all of a cell's DNA is packed into before reproduction

somatic cells

All body cells except the reproductive ones. Human somatic cells contain 46 chromosomes

Gametes

Reproductive cells (sperm and eggs). They have 23 chromosomes each in humans.

chromatin

The material that make up chromosomes. They're a complex of DNA and associated protein molecules.

sister chromatids

When a chromosome is duplicated, two sister chromatids are produced.

Centromere

In its condensed form, the duplicated chromosome has a narrow "waist" at the centromere, where the two chromatids are most closesly attached.

Mitosis

The division of the nucleus (see study guide for more detailed account.

Cytokenisis

The division of the cytoplasm

Meiosis

The process by which humans produce gametes. In meiosis, non-identical daughter cells are produced which only have one set of chromosomes-half as many as the parent cell. Occurs is gonads

Interphase

Much larger process than mitosis in which cell growth occurs and the cell copies its chromosomes in preperation for cell division

G1 Phase (Interphase)

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins

S Phase (interphase)

The Synthesis phase of the cell cycle; the portion of interphase where DNA is replicated

G2 Phase (interphase)

The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

G0 Phase (interphase)

A nondividing state occupied by cells that have left the cell cycle

Prophase

Chromosomes condense. The nucleoli disappear. Each duplicated chromosome appears as two identical sister chromatids joint at the centromere The miotic spundble begins to form.

Metaphase

Longest stage of mitosis, lasting up to 20 mins. Centromeres move to opposite ends of the cell. Chromosomes convene on the metaphase plate, a plane between the two poles.

Anaphase

Shortest stage of mitosis. Begins when the coheasion proteins are cleaved, which allows the two sister chromatids to suddenly part. By the end of this phase, the two ends of the cell have an equivalent set of chromosomes.

Telophase

Two daugther nuclei form in the cell. Nucleoli repapear. With this phase, Mitosis is complete.

Cytokenesis

Division of ctoplasm that occurs concurrently with Mitosis.

Diploids

A cell containg two sets of 23 chromosomes (ech inherited from one parent). So, 46 chromosomes total.

Haploids

Sexual or reproductive cells. Each only have 23 chromosoms.

Miotic Spindke

Consists of fibers made of microtubules and associated proteins

Centrosome

Site of spindle microtubule assembly.

Kinetochore

Structure of protein associated with specific sections of chromosomal DNA at the centomere. A chromosome's two kinetochores face in opposite directions

Cleavage

In animal cells, cytokinesis occurs through cleavage (characterized by the pinching of the plasma membrane) (2) The succession of rapid cell divisions without significant growth during early embryotic development that converts zygotes to balls of cells.

Cleavage Furrow

The first sign of cleavage in an animal cell; a shallow groove in the cell surface near the old metaphase plate.

Binary Fission

Asexual Reproduction in eukaryotes. Division in half.

Origin of replication

Site where the replication of a DNA molecule begins. COnsists of a specific sequence of nucleotides.

Cell cycle checkpoints

If conditions are not correct at any of these checkpoints, cell should not proceed through. (1) Fix Problem: can move past check point (2) Can't fix: cell suicide pathway (3) If not fixed and cell continues, cancer occurs.

Cancer

Unregulated cell division, cells can pass hrough checkpoints even if damaged or wrong

G1 Checkpoint

Checks cell size, DNA integrity: DNA is intact and in good shape. Most important checkpojnt in mammal cells. Also called the restriction point.

G2 Checkpoint

Checks cell size, completetion of replication and DNA integrity

M Checkpoint

Metaphase. Checks that all chromosomes attached to kinetochore tubule

Growth Factor

Protein released by a cell that stimulates other cells to divide

Receptors/Reception

Receptor is the cell to receive signal. SIgnal molecule binds to receptor and receptor is activated (shape change or chemical reaction modify)

Transduction

Converting external signal to internal message (relay molecules in signal transduction pathway)

Response to transduction

Activation of cellular response. Turn on cell control genes: activation of cell division

Little signal = BIG response

Transformation

Process that converts a normal cell into a cancer cell

Benign Tumor

When abnormal cells stay at the original site

Malignant Tumor

Travels to other parts of the body. Impairs the function of one or more organs.

Metastasis

The spread of cancer cells to locations distant from their original site.

Genes that if damaged, will lead to cancer?

growth factors, their receptors, intracellular molecules of signaling pathways

Proto-oncogenes

genes that encode signals, receptors, signaling molecules, control proteins, etc. If these genes are mutated they turn into oncogenes and cause cancer

Oncogenes

Cancer causing genes. Arrise from a genetic change that leads to an increase either in the amount of the proto-oncogenes protein product or in the intrinsic activity of each protein molecule.

Three types of genetic changes that convert p-oncogenes into oncogenes

movement of DNA within the genome, amplification of a p-oncogene, and point mutations in a control element or in the p-oncogene itself

Point mutations

mistakes in DNA replication, exposure to mutagen (UV light, tobacco), virus inserting DNA into gene. Abnormal protein can be hyperactive, tell cell to be "ON" all the time and continuously divide.

Gene Amplification

(Her2 example and herceptin). Normal protein, but way too much: over stimulate cell

Her2

Proto-oncogene, membrane receptor, when a signal molecule binds to Her2, genes are turned on : Stimulate cell division and inhibit cells from dying

Antibodies

proteins that recognize and bind specific molecules. Antibody made that can bind to Her2 receptors (Herceptin): blocks off binding site for receptors

Tumor Supressors

Proteins that inhibit cell division; shut down cell division if conditions are not favorable. Some detect and/or repair DNA damage (if mutated: override checkpoints). Some make sure cells are anchored (if mutates: cells invade other parts of the body). Normal and need to have them.

BRCA2/genetic testing

BRCA2 helps repair damaged DNA at G2. If mutated: damaged DNA but still go through mitosis; check point doesn't matter: increased risk for breast and ovarian cancer

p53

Helps cells decide wether to repair damaged DNA or commit cellular suicide. If damaged, can cause cervical cancer. A cell w/ damaged p53 doesn't make a cell decision, just divides and tumor cells proliferate

HPV and cervical cancer

DNA integrates into host genome, HPV proteins made, E6 and E7 proteins destroy p53.

Methylatin

Tumor supressors can be silenced by abberant methylation: no tumor supressor genes made: epigenetic phenomenon

Telomere

Ends of linear chromosomes, shorten with each cell division, after ~40 divisions, cell dies. Idea is that cells should die before they have had time to accumulate loads of damage

Telomerase

Enzyme that permits the entire telomere to be replicated, so chromosomes don't shorten. Almost all cancer cells have telomerase on. Telomerase activity detected in almost all tumors -> cell immortality. Mice enginerred w/ telomerase in all cells got cancer.

Antisense Drugs

Telomerase inhibitors. Single stranded nucleic acid complimentary to mRNA molecules made by cell.

Multi-step model of cancer development

(Step 1-2) Benign growth: localized mass of cells; (Step 3) Malignant growth: tumor cells invade neighboring tissue; (Step 4) Metastasis: cancer cells spread through lymph and blood vessels to rest of the body

Density dependant inhibition

Phenomenon in which overcrowded cells stop dividing. Prevent cells from mving forward in the growth process.

Chemotherapy

injection of cehmicals into blood stream to kill dividing cells. Some prevent mitosis. Taxol prevents MTs from shortening. Some stop DNA replication. Nonselective: will affect ANY rapidly dividing cells

Meiosis

The process in which haploid gametes (sperms or eggs) are formed

Fertilization

Produces diploid zygote. Egg + Sperm. 2n parent cell -> four 1n daughter cells.

Daugther Cells

Not identical to parent cells or to each other

Chromosomes replicate in what phase of cell cycle?

The S cycle

Prophase I

Chromosomes condense, SYNAPSOS: homologous chromosomes pair up. Paired state = bivalent. Crossing over occurs. Nuclear envelope breaks down, spindle formation like it mitosis (but in mitosis they do not pair up and there is no crossing over

Crossing over

exchange of genetic material between chromosomes (where cross occurs, chromosome can break)

Metaphase I

Homologous chromosomes line up on metaphase plate. Arrangement of parental and maternal chromosomes on metaphase plate is random: random alignment or independant assortment. Still needs to be in homologous pairs

Anaphase I

Homologous chromosomes moved to opposite sides of cell (sister chromatids still attached at centromere). Kinetochore MTs shorten and polar MTs lengthen as in mitosis

Telophase/Cytokenesis I

Each half of cell has complete haploid set of replicated chromosomes -> ready to go to meiosis II. In animal celss, cleavage furrow forms in mitosis. NO DNA REPLICATION.

Prophase II

If chromosomes decondensed in telophase I, they recondense here

Metaphase II

Chromosomes line up on metaphase plate (singly, as in mitosis)

Anaphase II

Seperation of sister chromatids

Telophase II/Cytokenesis

Nuclei form, chromosomes decondense, cleavage furrow

Final Outcome of Meiosis II?

4 haploid cells, different from parent, different from each other.

Sister chromatids

Either of 2 copies of a duplicated chromosome attached to each other by proteins at the centromere. While joined, two sister chromatids make up one chromosome, but they eventually split in meiosis or mitosis II

Homologous chromosomes

Two chromosomes of the same length, centromere position, and staining pattern

Genetic variation in humans is due to?

independant assortment

Independant assortment

random alignment on metaphase I plate. Alleles. During meiosis I, tetrads can link up two different ways before homologs seperate

How many possible combinations of maternal/parental homologs can you produce?

In general, diploid organism can produce 2ⁿ combination. n= haploid chromosome number. n= 23, so 2²³= 8.4 million different gametes

Fertilization and genetic variaton

8.4m x 8.4 mil = 70 trillion diploid

Nondisjuncton

members of a pair of homologous chromosomes or 2 pair of sister chromatids do not seperate properly. n + 1 = extra gamete, n - 1 = missing gamete

Anueploidy

Alteration on chromosome number

Monosomic

Occurs when fertilization involving a gamete that has no copy of a particular chromosome. Leads to missing chromosome in zygote. Can cause Turner's Disease

Turner's DIsease

Absence of an entire sex chromosome. Instead of being a normal XX female, there is only one X chromosome, and this leads to things like non-working ovaries, shortness, physical abnormalities.

Trisomic

Has one extra sex chromosome. Causes Down's syndrome.

Down's Syndrome

Caused by the rpesence of an extra sex chromosome and causes strange facial features, shortness, heart defects, and mental retardation. Also called trisomy 21.

Trisomy 13

Occurs when someone has three copies of genetic material from chromosome 13. Causes cleft pallate, clenched hands, extra fingers, seizures, undescended testicles, etc

Trisomy 18

Person has three copies of chromosome 18. Symptoms are clenched hands, mental deficiency, unusually shaped chest

Klinefelter's

Males, instead of being XY, are XXY. Causes small testicles and reduced fertility

Fetal Testing

Pre natal tests can be given to determine if a baby has a specific genetic defect

Maternal Age and Down's

The older the mother is, there is a MUCH larger chance of a child having Down's syndrome

Chorionic vilus sampling

8th-10th week of pregnancy. Placental sample is extracted and tested

Amniocentsis

14th-16th week. Extract amniotic fluid; culture cells for weeks; karyotype.

Cri du chat syndrome

Comes from a deletion at the tip of chromosome 5.

Deletion

Removes chromosomal segment, i.e. Cri du chat

Duplication

repeats chromosomal segment. Gene amplification. p-oncogene->oncogene, = cancer.

Inversion

reversal of a chromosomal segment

Recipricol Translocation

non-homologous chromosomes exchange fragments. This is the 3rd way in which a p-oncogene can become an oncogene. The oncogene encodes abnormal "fusion" protein. Fusion protein constantly activates a number of cell activites that normally are turned on when the cell is stimulated by growth factors.

P generation

The parental generation

F1 generation

The offspring of the P generation

F2 generatin

The offspring of the F1 generation

Allelle

alteranative version of the gene; both alleles can be the same or alleles can be different. Each organism has two alleles, one from each parent

Gene

A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA

True breeding strains

Fllowers, for example. Each generation must give rise to the same purple flowers for it to be a true breeding strain

Locus

A specific spot along the length of a chromosome where a given gene is located.

Dominant gene

Will always override a recessive gene at a given locus

Recessive gene

Will always be covered up by the dominant allele

Monohybrids

Organisms that are heterozygous for one character

Heterozygous

2 different alleles

Homozygous

2 identical alleles

Phenotype

physical traits of an organism determined by genotype

Genotype

The genetic make up, or set of alleles of an organism

Law of Independant Assortment

Each pair of alleles segregates independantly of other pairs of alleles during gamete formation.

Codominance

Means that two dominant genes and their phenotypes will both be distinctly seen in their offspring. For example, a Red and White Flower produce a red flower with white spots

Incomplete Dominance

The two alleles blend together. For example, a red and a white flower produce a pink flower

Test Cross

Breeding an organism of unknown genotype with a homozygous recessive individual to determine the unknown genotype. The ratio of the phenotypes in the offspring reveals the unknown genotype

Pedigree

A diagram of a family tree showing the occurence of heritable characters in parents and offspring over multiple generations

Methylation

Addition of molecules, like methyl groups (-CH₃) to the DNA backbone

Chromosome Packing

Change appearance and structure of DNA, which then changes gene expression

Eurochromatin

loosely packed (expressed)

Heterochromatin

Tightly packed (not expressed)

Barr bodies

A dense object lying along the inside of the nuclear envelope in cells of female mammals, representing a highly condensed, inactivated X chromosome. In Barr bodies, most genes are not expressed at all

X-inactivation

one X chromosome almost completely inactivated in embryotic development.

Epigenetics

any process that alters gene activity without changing the DNA sequence, leads to modifications that can be transmitted to daugther cells (gene turned on so protein can be made)

Cellular Respiration

We use chemical energy to carry out cell activites; electrons in chemical bonds of food have lots of chemical energy -> harness energy from bonds - > ATP

Glucose + O₂+ ADP + Pi --> CO₂ + H₂0 + ATP

See in class review diagram for more info

ATP

ATP = ADP + P

Protein is phosphorylated

Shape change/work

Where does cellular respiration occur?

Outer mitochondrial membrane, Inner mitochondrial membrane, Matrix and innermembrane space. In the mitochondria

Steps of Cellular Respiration

Glycolysis, The citric acid cycle, Oxidative Phosphorylation: electron transport chemiosmosis

Glycolysis

Sugars break down. Occurs in cystol.

Glucose > 2 pyruvate > into mitochondria.

Net gain of 2 ATPs (2 invested 4 gained)

2 NADH Also made

2 NADH, 2ATP, 2 pyruvates

Pyruvate Processing

2 pyruvates = NADH (x2), 2Acetyla CoA, and CO2 (x2)

Krebs Cycle

3NADH (x2), FADH₂ (x2), 2CO₂ (x2), and ATP (x2)

So, what do we have at this point in respiration (After Glycolysis, Pyruvate Processing, and Krebs Cycle) ?

4 ATPs have been made while ripping apart the glucose

What happens when glucose breaks down?

Bonds broken/new bonds form

Electrons get shuffled (we are interested in what happened to those electrons)

Substrate Level Phosphorylation

ATPs made by glycolysis, pyruvate processing and Krebs cycle formed by substrate level phosphorylation. Enzyme grabs P from a molecule (a substrate) and transfers it to ADP

But, 4 ATPs is NOT a lot of energy harnessed from those chemical bonds, and its NOT enough to run a multicellular organism

NADH and FADH₂

Electron storers/shuttlers. They give these electrons to the electron transport chain (ETC).

Electron Transport Chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP. Movement of electrons provides energy for H+ pumps

O₂ and the electron transport chain

Is the final acceptor of electrons in the electron transport chain

Cristae

Folds in the inner mitochondrial membrane that hold the electron transport chain.

Oxidative Phosphorylation

Produces 32-34 ATP. Formation of ATP through combination of proton pumping by ETC and action of ATP synthase: makes LOTS of ATP

ATP Synthase

H+ flows through ATP synthase complex through facilitated diffusion. Catalyzes formation of ATP, converts energy in H+ gradient > leads to ATP energy.

Active Transport

Movement of x across cell membrane. Uses ATP. Moves up concentration gradient

Facilitated Diffusion

Passage of molecules or ions across a biological membrane with the assistance of specific transmembrane transport proteins

Fermentation

Type of anerobic respiration.

Lactic acid fermentation: glycolysis>pyruvate + 2 ATP > lactic acid + NAD⁺

Alcohol fermentation: glycolysis > 2 ATP +pyruvate > ethanol + NAD⁺

DIgestion: Simple Animals use?

Direct Exchange. Lots of exposed surface area for exchangeMost animals have small outer surface compared to volume

Three Steps of Digestion?

ingestion, digestion, elimination

DIgestion: Complex animals use?

Specialized exchange surfacesExchange surface areas have large surface areaBody cells are bathed in interstitial fluid

Suspension Feeders

Method of ingesting where animals sift small food particles from water. Tunicate, baleen whale

Substrate Feeders

live in or on food source. Earthworm

Fluid Feeders

suck nutriet rich fluids from living host (humming bird)

Bulk Feeders

Eat relatively large pieces of food (humans)

Digestion

Breakdown of food into small enough pieces to allow for absorption

Mechanical digestion

Physical breakdown of food: breaking up food > increases surface area

Chemical digestion

Enzymatic breakdown of food

Turns:

polymer > monomer

polysacchs and diasacchs > monosacchs

proteins > amino acids

triglycerides > fatty acids and glycerol

Salivary amylase

starch/glycogen break down

Lingual Lipase

Fat Break down

Stomach and Digestion

Slimy bolus of food travels via esaphagus to the stomach by means of peristalsis, once in stomach churning, storage, digestion

Gastric Juice and Protein Digestion

Hydrochloric Acid, Pepsin (protein: digesting enzyme)

Why doesn't the stomach digest itself?

Pepsin remains in inactive form, pepsinogen. It seretes pepsin only when food is present so that way it doesnt eat away stomach lining.

Mucus cells secrete mucus that is a protective layer on top of the stomach layer

Stomach epitheleal cells > rapid mitosis

How are carbs digested?

Pancreatic amylase

Proteins?

trypsin and other protease from the pancreas

Bile

Made in liver, stored in gall bladder, emulsifies fat

Small intestine

Longer SI > more time for digestion, more surface area for absorbtion. Herbivores have evolved to have long SI and cecum.

Cecum

anaerobic chamber that contains cellulose digesting molecules.

How are nucleic acids digested?

Nucleases made by pancreas > nucleotides

Absoprtion (small intestine)

Uptake of specific nutrient molecules/ions

Small intestine has large surface area for absorption

Absorbtion II

Fats form chylomicron > lacteals

All other nutirents > capillaries > rest of body

Nutrients > Blood Stream > liver > rest of body

Fatty Acids combine w/ cholestorol and proteins to form chylyomicron > lacteal

Functions of the large intestine

Reclaiming water, elimination of solid wastes, mutualistic relationship with bacteria

Tight junctions in Intestines

connect cells lining intestines- you want food to go through cells, not between them. Holds cells together, inhibits movement of dissolved material thru spaces in the cell

Leptin

Hormone that regulates food intake. Produced by Adipose fat cells, most obese people have mutation in leptin receptor

Hormone

chemical messenger released into blood stream that acts on distant target cells. Secretion of digestive enzymes controlled by hormones

Hormones II

After eatign, stomach and SI release hormones that supress appetite

Leptin release and fat cell size?

Smaller fat cells secrete less leptin, so increase food intake, decrease metabolic rate and vice versa

Homeostasis

maintenance of constant internal conditions (normal fat cells maintained)

Negative Feedback

a change in variable triggers mechanisms that reverse that change- tells big fat cells to get smaller and small fat cells to get bigger

Colon

The largest section of the large intestine; functions in water absorbtion and formation of feces

Appendix

A small, finger like extension of the cecum, contains white blood cells that contribute to immunity

Esaphagus

Channel that conducts food, through perastalsis, from the pharynx to the stomach

Gall Bladder

An organ that stores bile and releases it when needed into the small intestine

Liver

The largest internal organ in the body. It performs diverse functions, like producing bile, preparing nitrogenous waste for disposal, and detoxifying poisonous chemicals in the body

Pancreas

Gland with dual functions: Nonendocrine portion functions in digestion, secreting enzymes and an alkaline solution into the small intestine. The ductless portion functions in homeostasis, secreting the hormones insulin and glucagin into the blood

Pharynx

In throat- food and air pass across.

Rectum

Portion of large intes. where feces are stored

Gas exchange occurs?

Between animals' mitochondria and external environment.

Involves ventilation, circulation, and cell respiration

Ventilation

movement of air or water across an exchange surface

Circulation

dissolved gasses transported through body via circulatory system

Common Features of respiratory surfaces

Thin (for diffusion), large surface area, Moist (gasses must be dissolved in water), composed of living cells

Diffusion

Spontaneous movement down a concentration gradient.

Intersitial Fluid

fluid filling the spaces between the cells of an animal

Gill

adapted for gas exchange in acquatic environment

Structure: out growth of body surface

Gill arch: holds many different gill filaments

How are gills ventilated

opening and closing mouth and operculum > pumps water and creates a pressure to ventilate gills

Swimming with mouth open, more flow of water, more oxygen

Gills and Gas Exchange

Gas exchange is hard in water; it contains much less oxygen than air and its harder to move across respiratory surface w/o air

Gas Exchange in fish

Flow of water over fish gills is unidirectional

Flows only 1 way

Gill arches hold filaments, each gill filament is richly supplied with blood vessels...water is always flowing over filaments in 1 direction and blood flows in OPPOSITE direction

countercurrent exchange

The flow of blood in the opposite direction to flow of water-very efficient mechanism to extract oxygen out of water.

*O2 in respiration surface always higher then )2 in blood because of concurrent flow

Tidal flow

The amount of water a fish inhales and exhales in concurrent exchange

Structure of Tracheal System?

Extensive system of tubules throughout the body, open and spiracles, which can close of if needed to minimize water loss

Do fish have circulatory systems?

No because gas exchange via tubules in contact with all cells in body

Ventilation: Small v Large insects

Small use diffusion, large use muscle contraction

Lungs Structure (5 parts)

trachea, lungs, bronchi, bronchioles, alveoli

Gas Exchange at alveolor surface?

alveolor of lungs is ourrespiratory surface: HUGE surface area

Gases move by simple diffusion into bloodstream; move dwon pressure gradients (high to low pressure)

Ventilation in humans

Negative Pressure breathing- we pull air into our lungs. Breath in, muscles contract, rib cage expands, diaphragm contrasts, volume of chest cavity increases so the pressure decreases, so air will go into lungs. When you breath out, diaphragm relaxes and air comes out

Air flow is tidal or non tidal?

Tidal: flows in and out through same pathway

Dont have gas exchange along entire respiratory surface Tidal is least efficient.

Residual Volume

air left in aveoli after exhalation (oxygen depleted dead air)

Ventilation in birds?

Uses crosscurrent exchange. Respiratory surface is parabronchi. Air sacs push aire through lungs

Is air flow in birds one or two way?

One way air flow through parabronchi

Airflow v. Blood Flow in birds

AIr flow is crosscurrent with blood flow.

Air flows in one direction

Gas exchange along ENTIRE respiratory surface

Efficiency: Crosscurrent v. Countercurrent flow

Counter current is more efficient than cross current flow

Bronchiole

Fine branch of the bronchi that transports air to alveoli

Alveoli

A dead end, multilobed air sacs where gas exchange occurs in the mamallian lung

Capillary

A microscopic blood vessel that penetrates tissue and consists of singlle layer of cells that allows exchange between blood and interstitial fluid. Essential in gas exchange.

What is blood composed of (2 parts)?

Plasma and Cells

Function of Circulatory System?

deliver nutrients, deliver gasses, remove waste, circulate hormones, immune function

Plasma

liquid part of the bloods

Ions, wast products, nutrients, hormones, gases, proteins (immune system, clotting)

Blood Cells and Function

RBCs (erythrocytes): transports O₂ and CO₂

WBCs (leukocytes): defense and immunity; platelets; clotting

Oxygen Transport in blood?

RBCS transport it. Theyre developed in bone marrow stem cells

Hemoglobin

O₂ carrying molecule. Composed of 4 polypeptin chain

Iron that binds with O₂
Each hemoglobin molecule can bind 4 O₂molecules

Is binding of O₂ reversible or irreversible?

Reversible

Cooperativity in O₂ binding?

O₂binds one subunit > other 3 subunites increase affinity for O₂

O₂ leaves one subunit > other 3 subunits readily unload O₂

Three types of blood vessels

Arteries: carry blood away from heart

Veins: return blood to the heart

Capillaries: convey blood between arteries and veins

Veins have what kind of valves?

One way valves. Force blood to flow towards the heart. If damaged = vericose veins.

Fish's Heart

Two chambered, single circuit = blood pressure issues, slow delivery of O₂to body tissues = less ATP = less activity

Amphibian's Heart

Three chambered, double circulation = NO blood pressure issues, Two atriums, Mixing of oxygen rich and oxygen poor blood

Mammal/Bird Hearts

Four Chambered Heart

Double circulation

SUpports Active, endothermic life

Where does O₂ exchange occur?

In capillaries, where the blood flow slows down.

Ectotherms

maintain body temp through behavior- less energy taxing

Endotherms

Expend more energy than ectotherms, have bigger lungs, and need 10X more calories than ectos

CO₂ Transport: 3 mechanisms

Some stays dissolved in plasma, some picked up by hemoglobin, MOST reacts with H₂O in RBCs and carried away as bicarbonate in PLASMA.

Advantages of closed cirulatory system>

Allows for regulation, Allows animals to be very active

Atrium

Chamber of the heart that receives blood from the veins and transfers it to ventricles

How does structure of different vessels fit function?

Arteries are thick walled, elastic, and muscular.

Capillaries are thin walled, beds have large diameter = slow blood flow maximum exchange

Single circulation?

Fish, slow blood flow, wont work on land

Three types of waste and how they're disposed of?

Food = Feces, CO₂ = respiratory, Nitorgeous waste = urine

What is nitrogenous waste and why is it harmful?

Nitrogen containing molecules break down into ammonia which is toxic to cells and further into ammonium ion which increases pH of cell, causing enzymes to denature

How do different types of animals get rid of nitrogenous waste?

Aquatic animals = ammonia, Mammals, amphibians, and others = urea, Birds insects, most reptiles = uric acid

The kidney

Urine formation, water conservation

Ureters

Transport urine

Bladder

Stores urine

Urethra

Passes urine to outside

Nephron function and parts

Functional part of kidney that makes urine

Surrounded by capillaries

Glomerulus

Ball of capillaries in the nephron, inside the Bowman's capsule- both make up the blood filtering unit

Proximal Tubule

Next to Bowman's capsule, conveys and refines filtrate.Want to get the good things back (salts, glucose, ions, vitamins, water)

What makes it to the proximal tubule?

anything that can fit- filtrate

Urine formation results from 3 processes:

Formation of pre-urine via filtration
Reabsorbtion of water, nutrients, and solutes
removal of water from the final urine via osmosis

Filtration

Extraction of water/small molecules (includes urea) from the blood; non selective process blood filtering unit: glomerulus + bowman's capsule

Unfiltered blood (blood cthat contains everything you want to get rid of)

Filtered blood (with big proteins, cells, and platelets)

Filtrate

Cell free fluid extracted from the body fluid by the excretory sytem

Unfiltered Blood

blood that contains everything you want to get rid of

Filtered Blood

Big Proteins, cells, and plateletes

Reabsorbtion

getting the good stuff from the filtrate back into the blood stream. Occurs in proximal tubule, which has epitheleal cells with microvilli that increase surface area

Loop of Heinle

BIGGEST part of water reabsorbtion. Filled with aquaporins. Water Whisked away by capilaries

Loop of Heinle: descending limb

permeable to H20, solute in medulla always higher than solute in desceding limb, so H20 can move by osmosis the entire way down.

Loop of Henle: ascending limb

permeable to salts, nonpermeable to water, creates concentration gradient

Length of Loop of Henle for freshwater fish, aquatic mammals, desert animals?

No loop

Shorter Loop

Longest Loop

Distal Tubule

Portion of the nephron that helps refine filtrate and empties it into the collecting duct

Final refining

More water reabsorbtion, now urine leaves collecting duct > renal pelvis

Activity of distal tubule and collecting duct regulated by hormones

Secretion in final refining

Toxins, excess ions ADDED to nephron, occurs and proximal and distal tubule

Regulation of final refining?

Antidiruetic hormone

Stimulates insertion of aquaporins in collecting duct
Brain cells release ADH drink more, drinking reduces blood

Negative Feedback

Change in physiological variable triggers mechanisms to counteract that change

Example: solute concentration % rises above set point -> ADH released - > triggers production of aquaporins -> solutes in blood diluted

Methylmolecule

Has the ability to shut down certain inherited traits, it "hides" the gene

Epigenetics: Epigenome v. Genome

Genome = hardware, Epigenome = software

Environmental Factors that effect epigenome?

The more one ages, the more epigenome changes. Food, smoking, drinking, life experiences, nurture

What can changes in epigenome produce?

Cancer and other diseases

DO epigenetics kill cells?

No, they just try to change their behavior

Famine Studies and Epigenetics

Famine can affect people almost 100 years later. Those whose grandparents suffered famine LESS likely to have negative epigenetic effects

Critical period of epigenetic development for males and females?

Females= when still in womb

Male = Late childhood

Exam 2 Flashcards

Zoology 101 with Bleiweiss\riters\thoma at University of Wisconsin - Madison

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