Biology 140-Final Study Guide

Biology 140 with Alexandre-jouline at University of Tennessee - Knoxville

About this deck

By: Sophie @Studyblue
Textbook:

Life: The Science of Biology
Created: 2011-04-22
Size: 120 flashcards
Views: 673

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Heterotrophs cannot obtain their energy directly from

sunlight

The tendency for an atom to attract electrons to itself in a chemical bond is called

electronegativity

Because atoms can have the same number of protons but a different number of neutrons, elements have

isotopes

The ability of atoms to combine with other atoms is determined by

the number and distribution of electrons

Each of the following can participate in H-bond formation except

C6H6

The difference between an acid and a base is that an acid whereas a base .

releases H+ ions in solution; releases OH- ions

The optimum pH for growing strawberries is 6.5, whereas the optimum pH for growing blueberries is 4.5. Therefore, the number of hydrogen ions needed to grow strawberries is times the number needed for blueberries.

100

Which of the following best represents the backbone arrangements of two amino acids with a peptide bond?

N-Ca-C-N-Ca-C

Which of the following pairs is not a correct monomer/polymer pairing?

Triglceride/cellulose

With the exception of Glycine, all amino acids found in proteins are of

L-form

Amino acids can be classified by the

characteristics of their side chains-"R" groups

Which of the following is characteristics of proteins?

Some function as enzymes

The side chain of leucine is a hydrocarbon. In a folded protein, where would you expect to find leucine?

In the interior of a cytoplasmic enzyme and on the exterior of a protein embedded in a membrane

An a helix is an example of which level of protein structure?

Secondary

Forces involved in folding of a protein into its native conformation include

hydrogen bonding, hydrophobic interactions, and electrostatic attraction

The difference between a and b-glucose is

in the orientation of OH and H atoms of the anomeric Carbon

DNA and RNA contain

pentose

Cellulose is the most abundant organic compound on Earth. Its main function is

to provide mechanical strength to plant cell walls.

Polymerization reactions in which polysaccharides are synthesized from monosaccharides

result in the formation of water

The tertiary structure of a protein is determined by its

interactions among side chain R groups

Which of the amino acids listed below would, when incorporated into a polypeptide chain (not at the N- or C-terminus), make the charge of the polypeptide more positive?

Arginine

Which of the following protein structures is/are destroyed by denaturation

Secondary and Tertiary

Lipids are

insoluble in water, hydrophobic, and important for energy storage

Triglycerides are synthesized from

fatty acids and glycerol

A phospholipid differs from a triglyceride in that phospholipids

have both hydrophylic and hydrophobic parts

What is the result of decreasing the number of double bonds?

The oil is now a solid at room temperature

The "backbone" of nucleic acid molecules is made of

alternating sugars and phosphate groups

Which of the following is NOT a difference between DNA and RNA?

DNA is a polymer and RNA is a monomer

DNA carries genetic information in its

sequence of bases.

The amino acid substitution that is likely to cause the largest change in tertiary structure is

lysine to isoleucine

Chperonins

help polypeptide chains to fold correctly in the cell

Which of the following is an amino acid not found in protiens

Ornithine

Which of the following are principles on which to base column chromatography?

size, charge, and hydrophobicity of the protein.

Which set of amino acids would you expect to find on the surface of protein molecules found w/in the interior of biological membranes?

Ala, Phe, Leu, Met

Cell membranes typically display asymmentry. This means

The two leaves of a bilayer contain different collections of lipids and proteins

The plasma membranes of winter wheat are able to remain fluid when it is extremely cold by

replacing saturated fatty acids with unsaturated fatty acids

Which of the following cell membrane components serve as recognition signals for interactions between cells?

Glycolipids or glycoproteins

To which class of large biological molecules does the unknown liquid most likely belong?

Lipids

What is the nucleotide sequence of the complementary strand of the the DNA molecule: AATGCGA

TTACGCT

In addition to the bilayer lipids and proteins, membranes may contain in the form of and .

Carbs, glycoproteins, glycolipids

Characteristics of most living organisms include:

one or more cells, genetic information, and can regulate internal environment

Structure of a muscle

fiber, many nuclei, sarcolema, myofibril, thin filaments

sarcolema

plasma membrane

myofibril

contractile structure, with thick/thin filaments

thin filaments

contain actin

thick filaments

contain myosin

A band

defined by the length of the myosin, overlaps the actin

thick filaments attach to the mid line in A-band

H zone

defined by myosin, no actin, no overlap

I band

defined by the actin, no myosin, no overlap

Z disc

boundary of the sarcomere, where the filaments attach

Sarcomere

functional unit of striated muscle with thick and thin filaments

(Z to Z)

Sliding Filament Model

- filaments do not change length
- I bands contract
- A bands stay the same
- degree of overlap changes, sarcomere is shorter

Muscle contraction

myosin head groups = cross bridges

they are extensions of myosin filaments

Myosin

- 6 polypeptide chain
- tail and head (up to clusters of 300!)
- head group attached to the actin

Actin

- globular protein monomer unit
- G actin (globular) = 375 AAs can polymerize to long chain
- F actin (filamentous)

Contraction

requires ATP

myosin is a protein, head group is an ATP-ase

Steps of the "Sliding Filament Model"

- actin any myosin are bound
- ATP bind to myosin, causing dissociation of actin-myosin
- ATP hydrolyzed (by water) to ATP + P (P is still attached)
- myosin re-attaches with ATP + P
-phosphate is released, energy is released ----> protein conformation change
- "rigor" state = no ATP, cross bridges do not dissociate

Calcium

triggers the contraction

tropomyosin, troponin

two associated proteins of actin

troponin has three polypeptides, one is troponin C

Steps of Calcium

- myosin binding site on actin is blocked by tropomyosin
- calcium binds to troponin C
- conformational change of troponin pushes tropomyosin away
- allows myosin to bind

Stimulation proccess of Calcium release

- muscle receives signal from the brain
- nerves release acetylcholine ( a neurotransmitter)
- propagates a signal (does not bathe the muscle)
- signal to cell membrane; stimulate a change in flow/voltage
- voltage change over entire membrane

Calcium

released by sarcoplasmic reticulum (specialized ER)

sarcoplasmic reticulum

- reservoir of calcium
- transverse tubule signals SR to release calcium = calcium release
- attached to troponin C

Smooth muscle

- gives shapes to hollow organs
- must stay contracted for long period of time
- no striations... actin and myosin are criss-crossed
- individual spindle-shaped cells with individual nuclei

Spindle-shaped cells

- actin and myosin, but no myofibrils
- has 2X the actin, 1/4 the myosin
- myosin has no bare central region
- has "dense bodies"; fibers attach obliquely
- slower muscle contractions

Cardiac muscle

- has actin and myosin
- individual cells with own nucleus and membrane
- intercalated discs
- Ca+ binds to troponin C
- highly oxidative
- not activated by nerve impulses

intercalated discs

a membrane partition with gap junctions

Slow twitch

more mitochondria than fast twitch
higher capacity for aerobic metabolism
high oxidative capacity
high myoglobin = contains iron

RED meat

Fast twitch

moderate amounts of mitochondria and myoglobin
WHITE meat
high glycolytic capacity = anaerobic exercise
low oxidative capacity
faster time to peak tension
more developed sarcoplasm reticulum (faster release of calcium)

Slow twitch

higher capillarization
catabolism of FATS = prolonged exercise

VO2 max

- maximal rate of oxygen consumption
- single best measurement of cardio-respiratory endurance and aerobic fitness

creatine phosphate (phosphocreatine)

energy storage molecule
breaks down and drives a P onto ADP
prevents ATP depletion
will last about 3-15 seconds, then dependent on glycolysis

Anaerobic threshold

intensity of exercise where there is an abrupt increase in PCr hydrolysis and glycolysis, resulting in increased lactate

Anaerobic Capacity

maximal amount of ATP able to be regenerated from PCr and glycolysis during intense exercise

Mendel (1865)

"elements" that carried inherited information

Darwin (1859)

"Origin of Species"

Miescher (1869)

DNA discovered, called nuclein

proteins

were initially thought to be numerous and variable, were also thought to be genetic material

"tetra-nucleotide theory"

DNA was thought to consist of a monotonous repeat of bases
DNA was thought to be identical in all organisms

Beadle and Tatum (1930s)

discovered that genes code for proteins

Chargoff (1940s)

most were not convinced that DNA was genetic material
discovered that % Guanine = % Cytosine, % Adenine = % Thymine....
.....and was species specific

mid 1940s-1950s genes were found ti be made from DNA

Purines

2 rings (5 carbon, 4 nitrogen)

Pyrimidine

one ring (4 carbons and 2 nitrogen)

Race for the structure of DNA

Watson and Crick, Linus Pauling, Rosalind Franklin and Maurice Wilkins

Rosalind Franklin

foud x-ray diffraction to show that DNA was a constant diameter (idea was stolen by Watson)

Steps in DNA replication

- mediated by DNA polymerase (endergonic)

1. each DNA strand serves as a template for a new strand
2. bases enter at attachment points as a triphosphate at 3' end
3. two phosphates are cleaved (pyrophosphate)
4. hydrogen bonds form with template base

DNA

DNA unwinds, forms a "replication bubble"

"replication fork" moves in opposite directions until replication is complete

leading strand

synthesis is done by normal DNA polymerase

lagging strand

3' => 5' and DNA polymerase won't do this
1000 bases long
requires a short primer of RNA, not of DNA

DNA polymerase

uses 3' end of RNA primer to begin synthesis
occurs in fragments called "Okazaki fragments"

Mistakes in DNA

damage can be caused by chemicals, UV lights

common mistakes:
depurination, deamination, thymine dimers (UV radiation)

these all result in mistakes in final proteins

PCR

requires a synthetic "polynucleotide" primer for each end

Step 1:
- heat DNA so it unravels
- decrease heat; primer attaches
- elongation....nucleotides attach
- rise in temperature halts step one
- repeat

Genetic Fingerprinting

- only 3-5% of genome codes for protein
- coding regions of genome are highly conserved; non coding regions are not conserved
- large bits of repeating VNTRs
- bits inherited from Mom and Dad are different lengths

RNA - 1960s

discovered to be an intermediate in protein synthesis

because:
DNA in nucleus, RNA in cytoplasm
protein made in cytoplasm ... RER
ribosomes made from RNA

Crick's Central Dogma

DNA specifies RNA which specifies proteins

DNA vs RNA

Single (RNA) vs double (DNA)
uracil (RNA) vs thymine (DNA)
RNA can form base pairs within same molecule, or between different molecules

Kind of RNA

mRNA
tRNA
rRNA (2 sub units)

Protein synthesis

- DNA is blueprint for a protein; stays in the nucleus
- DNA unwinds
- DNA base sequence is copied to mRNA
- DNA code, now sitting on mRNA, goes to ribosome (in cytosol)
- DNA is translated on ribosome to a protein

Genetic Coding

4' = 4 possible AAs
4'' = 16 possible AAs
4''' = 64 possible AAs (triplet code)

Nirenburg (1961)

- looking at protein synthesis in bacteria
- artificially produced poly-Uracil
- which produced poly-phenylaline
- first demonstration that base sequence on RNA = order AAs

MIXED RNAs (with Adenine and Uracil) would make 8 possible AAs (2''' = 8)
^ demonstrates that mRNA is read sequentially in threes

Transcription

mediated by RNA polymerase
transcribes mRNA bases onto 3' end
does not need a primer
copies only one strand of DNA - the "template strand"

Steps to Transcription

1. Initiation
2. Elongation
3. Termination

Step One: Initiation

DNA unwinds
RNA binds at promoter site
"initiation site" is where first nucleotide is copied onto mRNA

first ribonucleotide attaches as a triphosphate

Step two: Elongation

- addition of more ucleotides "residues"
- mRNA grows from 5' end to 3' end (RNA polymerase reads template DNA from 3' to 5' end)
- growing mRNA molecule detaches from template
- helix re-forms

Step three: Termination

RNA polymerase encounters "termination sites"
RNA polymerase detaches from DNA template

Primary Transcripts and Mature mRNA

- only 3-5 % of genome codes for protein
- when DNA is transcribed, non-coding regions are transcribes too
- this results in a strand of "pre-mRNA"..... a "primary transcript"

Processing

eukaryotes only

- mRNA capped at 5' end with GTP
- this stabilizes the transcript; protects from enzymes that degrade at 5' end
- string of adenines (50 - 200) added to the 3' end
- this also stabilizes the mRNA transcript

Mature mRNA

- non coding regions need to be removed for this to happen
- Intron - non-coding DNA that is still transcribed
- Exon - coding region that is expressed
- mature mRNA are exported to cytosol and to the ribosome

Translation - the ribosome

site of protein synthesis
2 sub units
note conserved structure!!
each sub unit is made of RNA (structural) and protein

rRNA is coded for by rDNA (in nucleolus)
about 280 copies of genes for rRNA exist

Transfer RNA

coded for by DNA
made in nucleus
about 75-80 bases long
40 different kinds: each tRNA carries with it a specific AA
tRNA has a cloverleaf shape (internal base pairing)
one end has the anitcodoon; other end carries an amino acid

"charged" tRNA: hooking the amino acid to tRNA requires enzymes and energy
enzyme has binding sites for ATP, AA, tRNA

Steps to Translation:

1. Initiation
2. Elongation
3. Termination

anabolic reactions

free energy + small molecules --> complex molecules
simple molecules to form more complex molecules. may make a single product, such as a protein (highly ordered) out of amino acids (less ordered) require or consume free energy ENDERGONIC

first law of thermodynamics

in any conversion of energy from one form to another, the total energy before and after the conversion is the same

second law of thermodynamics

disorder tends to increase; when energy is converted from one form to another, some of that energy becomes unavailiable to do work.

irreversible inhibition

inhibitors covalently bond to certain side chains at active site of an enzyme, permanently inactivating the enzyme by destroying its capacity to interact with normal substrate

reversible inhibition

inhibitors similar enough to particular enzymes natural substrate to bind non covalently to active site but different enough to not catalyze a chemical reaction

interphase

the condition a eukaryotic cell is in for most of its life

nondisjunction

a pair of homologous chromosomes may fail to separate in meiosis 1, or sister chromatids may fail to separate during meiosis II or mitosis

centrioles

each centrosome consists of a pair, each one hollow tube lined with 9 microtubules

About this deck

By: Sophie @Studyblue
Textbook:

Life: The Science of Biology
Created: 2011-04-22
Size: 120 flashcards
Views: 673

About StudyBlue

“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis