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protons, neutrons, and electrons.
polysaccharides coating the outer layer of the plasma membrane
Supports the cell, maintains its shape, and functions in cell motility
Supports kind of like train tracks and support beams in the cell
Control center of a eukaryotic cell.
"Before the nucleus"
A phospholipid has a hydrophilic head and hydrophobic tails (fatty acids)
All chemical reactions can occur on their own, but slowly. Have to get over activation energy.
Requires the use of cellular energy
The diffusion of substances (across cell membranes) down concentration gradients
Is a passive transport where small molecules diffuse down a concentration gradient with the help of a transport protein (channel or carrier)
Diffusion of water across membranes
Membrane proteins use energy (ATP) to move molecules across plasma membranes against their concentration gradients.
Cells engulf particles or fluids in the cell.
The capacity to do work, every organism requires a constant supply of external energy to remain alive.
The energy that is contained in molecules and released by chemical reactions
A process that forms or breaks the chemical bonds between atoms
are used to break down molecules & release energy (kinetic) to do work
are used to build molecules and store energy (potential)
Scientific Theory vs. Everyday Theory:
- solar energy is trapped and stored as chemical energy in the bonds of sugar (glucose)
- endergonic reaction
- energy+carbon dioxide+water= glucose+oxygen
- two processes= light reactions and calvin cycle
- "photo"= capturing sunlight
- "synthesis"= refers to making glucose
Process by which solar energy is trapped and stored as chemical energy in the bonds of a sugar (glucose) molecule
Leaves obtain CO2 and release O2 as waste through pores called stomata
- organelles with a double membrane enclosing a fluid; FLUID; like cytoplasm
- Calvin Cycle occurs here!
- embedded in the stroma; disk-shaped membranous sacs
- light-dependent reaction of photosynthesis
- chlorophyll captures sunlight energy and converts some of it into chemical energy
- stores in the energy-carrying molecules ATP and NADPH
Occurs in the stroma (fluid inside the chloroplasts)
The build up of O2 to toxic levels: eventually death
Plants are faced with a choice:
plants have evolved to avoid photorespiration; two types:
1. C4 Pathway= uses special mesophyll and bundle sheath cells to minimize photorespiration (dry environment)
2. CAM= performs different activities based on the time
these plants can be subject to photorespiration during harsh conditions
*REGULAR= PLANT DIES!*
the scientific method tests a single variable at a time.
The number of protons is unique to each element, the number of proton's is referred to as the atomic number.
The atomic number of each element is in top right.
is the total moss of its protons, neutrons, and electrons. BUT electrons are negligible of weight.
So, atomic mass= Protons + neutrons
distributed around the nucleus of an atom in electron shells.
By interacting with other atoms in losing, gaining, or sharing electrons
Interactions between atoms: chemical bonds
Sharing of electrons lead to covalent bonds.
If electrons are shared evenly, a bond is nonpolar (uncharged)
If electrons are not shared evenly, a bond is polar (uncharged)
Happens only in compounds (different elements)
Atoms with the most protons pulls more on the shared electrons, electrons spend more time around one atom (now-) and less time around other atoms (now +)
Polar covalent bonds (like H2O) produce positive and negative regions.
Water-based solutions can be acidic, basic, or neutral.
H+>OH- are acidic
ex. lemon juice and vinegar.
OH->H+ are basic
ex. Baking soda, Chlorine bleach, and Ammonia
OH-=H+ are neutral
ex. Pure water
pH 0-6 is acidic (H+>OH-)
pH 7 is neutral (H+=OH-)
pH 8-14 is basic (OH->H+)
small organic molecules (called monomers) are joined to form longer molecules (called polymers)
Monomers are joined together through dehydration synthesis.
Polymers are broken apart through hydrolysis: "water cutting"
carbohydrate molecules are sugars.
A carb of just one sugar molecule.
2 linked monosaccharide form a disaccharide.
A polymer of many monosaccharide's
age American consumes over 40 pounds per year.
Sucrose (table sugar)= glucose + fructose
Lactose (milk sugar)= glucose + galactose
Maltose (malt sugar)= glucose + glucose
Non- digestable disaccharide:
Artificial sweeteners= insulin release, even though they are calorie-free
FDA lists these as "GRAS" (gen. known as safe)
Chains of simple sugars, 2 main functions:
Solid at room temperature
Liquid at room temperature
Unsaturated fats artificially changed into saturated fats
Amino acids are joined to form chains by dehydration synthesis:
Proteins only function when folded into the appropriate structure, all are unique.
Amino acids linked together in a protein
A helix or pleated sheet
More complex folding due to many types of bonds
multiple proteins linked together
Disruption of bonds= disruption of folding= denaturation
Means permanent loss of function in protein
Regulates what goes in and out of a cell.
All fluid and structures inside the plasma membrane, but outside the nucleus.Fluid portion: Cytoplasmic fluid
Yes, it's a flexible membrane because it's basically fluid and they are not bonded to one another.
Some phospholipids have unsaturated fatty acids that causes "kinks" in the tails, which means more fluid.
Cholesterol reduces fluidity and permeability, all animal cell membranes have cholesterol(how easily things get through the membrane)
Breaking chemical bonds releases kinetic energy
Enzymes Cont. :
Enzymes make reactions occur fast enough and regulate all chemical reactions in cells.
many medicines are designed to block or mimic enzyme activity.
enzymes: proteins which are folded into complex structures to function.
6CO2 + 6H2O + Light energy= C6H12O6 + 6O2
Carbon dioxide + water + sunlight= Glucose-sugar + Oxygen
Reactants (low energy) + Energy= Product (high energy)
Splits glucose into 2 pyruvates and 2 ATPs
2 pyruvates (created by glycolysis) move into the mitochondria, because it creates the most energy
Involves 3 steps:
Cellular Respiration "Equation":
pyruvate + O2 -> 34 or 36 ATP + CO2 + H2O + heat
Glucose-> 2 pyruvates + 2 ATP
1 parent cell divides to make 2 daughter cells- "Mitotic cell division"
Interphase: a time for acquisition of nutrients, growth, & chromosome duplication
G1 (growth phase 1): acquisition of nutrients & growth to proper size
S (synthesis phase): DNA synthesis -every chromosome is replicated
G2 (growth phase 2): completion of cell growth & preparation for mitotic cell division
Specialized cell division process that makes haploid gametes (sperm or eggs)
Meiosis 1: separates the duplicated pairs of chromosomes- each daughter gets one pair 1-> 2
Meiosis 2: separates the homologues & puts one chromosome into each daughter cell 2--> 4
Also has unique stages (prophase, metaphase, anaphase, and telephase)
A benign tumor is a large, but normal, mass of cells that is stationary.
Dangerous cancer cells are malignant
Carry the same genes for the same characteristics at the same loci
If both chromosomes carry the SAME allele, the organism is homozygous
Females have two X chromosomes
Males have an X chromosome and a Y chromosome
Some genes only found on the X chromosome is important for both sexes
A sex linked trait caused by recessive alleles on the X chromosome, afflicted person can't distinguish between red and green.
Females can be X-R X-r, X-R X-R, or X-r X-r
Males can be X-r Y or X-R Y
If they inherit the recessive they cant mask it.
this means males are 16X more likely to be color blind
The presence of antibodies means that blood type must be matched carefully before a blood transfusion is made.
Heterozygous parents can show unaffected phenotypes but be carriers of the recessive allele
less common; must have both recessive alleles in genotype to express the phenotype
ex. sickle cell anemia
A dominant disease can be transmitted to offspring if at least 1 parent suffers from the disease.
ex. Huntington's disease
The incorrect separation of chromosomes in meiotic cell division.
1. phosphate group,
2. monosaccharide (simple sugar)
3. bases; A, T, C, G,
nucleotide is usually referred to by the letter representing the base.
The bases pair in a precise combination:
DNA= double helix
Double: 2 nucleotide strands connect together (like a ladder)
Helix: the nucleotide strands are then twisted like a corkscrew or circular stair case
DNA replication begins with enzymes called DNA helicases, that pull apart the parental DNA
When replication is complete, each parental strand and daughter strand wind together into a new DNA double helix
The resulting DNA has 1 old parental strand and 1 new strand- semiconservative replication
changes in the sequence of bases:
occurs when a chunk of DNA (often very large) is removed form 1 chromosome and attached to another chromosome
Only time more than one chromosome is involved
The information in a gene is copied into RNA (DNA-> mRNA)
Initiation: DNA helix is split near the start of the gene (unzipped) , short series of DNA bases called a Promoter Region signal the start of the gene
Elongation: RNA polymerase (an enzymes) pairs RNA nucleotides with the DNA until the end of the gene
A with U & C with G
Only 1 side of the DNA is copied (called the template strand)
tRNAs move in and out of the ribosome, leaving their amino acid behind attached to the last amino acid.
This process continues 1 codon at a time, until a stop codon is reached: termination
Short series of DNA bases called the termination signal, signals the end of the gene
mRNA strand is released and DNA re-zips
The 1st duplicated mRNA strand= pre mRNA
finished spliced mRNA, tRNA, and ribosomes cooperate to synthesize proteins
Codons on mRNA are "read" in order and the matching amino acids are assembled into a protein
mRNA, tRNA, Amino acids, and ribosomes synthesize a protein using the info carried by mRNA
RNA "translated" to proteins: changing from one kind of biological molecule to another. RNA & proteins= different "languages"
When mRNA leaves the nucleus, it can then bind to the ribosome in cytoplasm.
A misreading of a gene's codons during transcription or replication, ex. deletion and insertion
changing the codons changes the amino acids coded for and almost always results in a non-functional protein.
many amino acids are encoded by more than 1 codon
A point mutation sometimes does not change the amino acid sequence of the protein. ex. UUA and UUG both code for leucine
makes it neutral.
the ability of a cell to control which genes are used or not at any given time.
occurs at 3 different levels:
transcription- which gene in a cell is expressed
translation- how much protein is made from mRNA
protein activity- how long the protein lasts in a cell
the use or alteration of organisms, cells, or biological molecules to produce food, drugs, or other goods.
ex. making beer and bread and sequencing DNA
Alteration ex. GENETIC ENGINEERING: modifying genes. transgenic animals and genetically modified organisms
DNA profiling can be used to identify a person. ex. paternity tests or criminal investigations
DNA profiling was used in court for the first time in 1986 to exonerate a man wrongly convicted of murder and rape, now used whenever possible
Project launched in 1990 to determine the nucleotide sequence of all the DNA in our entire set of genes (our genome)
Most human DNA is the same for everyone on the planet. BUT: examining the genomes of many individuals uncovers the varying alleles.
May correlate with med. conditions, predispositions to a disease, and diff. responses to treatments, we can aid in treatment by knowing.
Comparison of our genome with those of other species will clarify the genetic differences that make us human.
A common modification to crops= improving insect and herbicide resistance.
Used to produce medicines, medically useful genes can be inserted into plants
Genetically modify animals to our benefit
GMO's in the US have no labeling or health research required by companies. Put the burden of proof into companies hands
unsettling results from others opposed to the companies results - linked to diseases and illnesses
herbicide resistance can be transferred to wild plants
Stage of development with rapid growth and the appearance of secondary sexual characteristics in both sexes
between ages 8-15
Brain maturation at puberty causes the release of LH and FSH.
LH and FSH stimulate:
Surrounding each egg is a layer of smaller cells, together these cells and egg make up the follicle
each month females develop a new follicle
As the follicle matures, it becomes larger and fills with fluid. --ovulation occurs when the follicle erupts through the surface of the ovary
Most follicle cells remain in the ovary
Most follicle cells remain in the ovary:
Each ovary nestles within the open end of a uterine tube (also called the oviduct or fallopian tube)
The inner lining of the uterus, or endometrium, is richly supplied with blood vessels and nutrients
The muscular wall of the uterus, contracts during childbirth, expelling the infant out of the uterus
Testes--epididymis--vas deferens-- urethra
Epididymis and vas deferens= tubes that store and conduct sperm (aprox. 1)00 mill sperm produced a day and stored)
Urethra: conducts urine out of the body during urination, and sperm during ejaculation
an operation in which the vas deferens leading from each testes can be severed and tied, clamped, or sealed.
- sperm still produced, but can't leave epididymis, removed as waste
- ejaculation occurs normally but sperm-less
- in most cases you can reverse a vasectomy
An operation in which the uterine tubes can be clamped or cut.
- ovulation still occurs and hormone level do not change, but sperm can't travel to the egg, nor can the egg reach the uterus
- reversal tubal ligation, in most cases the uterine tubes can be reconnected.
Preventing Ovulation: hormone treatments such as the pill, include just enough progesterone to prevent ovulation.
Preventing sperm and egg from meeting: condoms, diaphragms, and sponges
Preventing implantation in the uterus: an IUD Intrauterine device is inserted into the cervix and prevents implantation if sperm do fertilize the egg
ex. birth control pill
- alters hormones to prevent ovulation
- when used currectly, prevents pregnancy over 99% of the time.
Male and female condoms can be used during sex act to prevent egg and sperm from meeting
- when used correctly, prevents pregnancy over 85% of the time
- offers some protection against STDs
IUDs- Intrauterine device
-placed inside the uterus
-impairs sperm motility and irritates the lining of the uterus, making it hard for embryos to implant
-when used correctly, prevents pregnancy over 99% of the time
-can last over 10 years
Comes as a gel, foam, or even film and suppositories
- kills sperm on contact
-inserted into vagina
-70% of the time
- can be effective when paired with condom if it is broken and a few sperm enter the vagina.
-causes tissue irritation and can increase risk of HIV and STDs
Involves abstaining from intercourse during ovulation
- high failure rate because cycle varies each month, making ovulation difficult to predict
- sperm can survive for several days in female reproductive tract
Coitus Interruptus or "pull out method"
- removing penis from vagina just before ejaculation
-potentially unreliable b/c of pre-ejaculation and user error
attempting to wash sperm out of vagina before they have entered the uterus
-reduces chances by 30%
increase risk of problems during pregnancy
unhealthy vaginal environment
"Morning after pill" - contains high doses of the same hormones as in birth control pills
-acts primarily by preventing ovulation, but may also prevent implantation
-effective if taken within 72 hours, but ideally within 24 hrs of intercourse
-75 to 90% effective depending onhow long you wait
final testing phase.
- very small injection of a gel into the vas deferens
-gel hardens to the sides, allowing sperm to pass but destroying them as they do.
-safe, nontoxic, and can last over 10 yrs
Terminates, not prevents.
- performed by dilating the cervix and removing the embryo, usually within first 3 months of pregnancy
- can also be induced during first 7 weeks of pregnancy by the drug RU-486
- distrupts the uterine lining during pregnancy, expelling embryonic tissue
Common symptoms: painful urination and discharge in both males and females
Can: cause infertility in women after a while
-700,000 new cases each year in US
-62 mill cases globally ever year
-treated with antibiotics (curable)
-rarer in developed countries like US
Common symptoms: ulcer or lesions on outer sexual organs or even on cervix, rash, fever, pregnancy complications, neurological symptoms, and death
-some show no symptoms and can be treated with antibiotics
Common symptoms: fever, painful urination, burning, and discharge in both males and females
Can= infertility in women if untreated for long
-some men and 70% of women show no symptoms at all: Silent Epidemic
-most common bacterial STD, 2.8 mill new cases in US every year
- can spread from genitals to cause eye infections and blindness
Human immunodeficiency Virus/ Acquired immunodeficiency syndrome
- currently a global pandemic
-17,500 people die of AIDS per year in US
- Causes immune deficiency and is eventually fatal
-asymptomatic for months and even many years
- no cure but some drug combos can slow the progression and can keep the disease under control for many years
- AIDS functionally cured?
Small single-celled organism that causes itching and burning in genitals and discharge
-men often have no symptoms
-affects 170 mill people worldwide every year
-can be cured but prolonged infections can cause sterility, problems with pregnancy, and increase risk for cervical cancer
-Tendril-like projections of Trichomonas protozoa latch on to genital tissues
-live and lay eggs in pubic hair
-suck blood from genital area: itching and soreness
-2% of people are affected worldwide
-can also spread other infectious diseases
-killed with insecticides
-not prevented by condoms
-can also spread through shared towels, clothing, bedding, or closets
- Watson and Crick= developed 3D model of DNA (double helix)
- Wilkins and Franklin= figured out how to take x-ray pictures of microscopic things
- COLLABORATION led to discovery of DNA structure
- type of nucleic acid (organic/biological molecule) made up of chains of nucleotides (monomers)
- three components=
1. a phosphate group
2. a sugar; monosaccharide
3. a nitrogen-containing base
- sugar-phosphate backbone has covalent bonds= STRONG
- bonds= Adenine, Guanine, Thymine, Cytosine
- bases are bonded by hydrogen bonds= WEAK :)
- DNA Helicase= pull apart parental DNA double helix (unzip)
- DNA Polymerase= pairs free nucleotides with conplementary nucleotides
- RNA Helicase= in Chapter 12
may have varying effects on function
1. Point (nucleotide substitution)= changes individual nucleotides
2. Insertion= one or more new nucleotide pairs are inserted
3. Deletion= one or more nuclotides are removed
4. Inversion= piece of DNA is turned around
5. Translocation= when chunk of DNA is removed from one chromosome and attached to another
- mutations are often harmful; organism may die quickly (ex: cancer or birth defects)
- some may have no functional effect: neutral
- some may be beneficial and provide an advantage in certain environments
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