AP Biology Ultimate Flashcard Set

Water moves

High to low water potential

Low to high osmolarity

Low to high solute concentration

Hypertonic solution

draws water out of cell

Hypotonic solution

cell swells and could lyse

Isotonic solution

In equilibrium

1st law of thermodynamics

Energy cannot be created or destroyed, only transferred or transformed

e.g. photosynthesis (radiant to chemical), consuming to climb tree (chemical to kinetic)

2nd law of thermodynamics

Energy transformation increases the entropy of the universe

e.g. trophic levels 90% heat loss only 10% efficiency for endothermic individuals

Exergonic versus endergonic

exergonic releases energy e.g. cellular respiration; change in free energy < 0

endergonic absorbs energy e.g. photosynthesis; change in free energy > 0

3 types of work cells perform

Mechanical (beaten cilia, chromosome movement, contraction of muscle cells via microfilaments)

Transport (pumping substances across membranes)

Chemical (molecule e.g. protein synthesis)

ATP

Adenosine Triphosphate: Adenine + Ribose + 3 phosphate groups

Obtain energy by breaking bond between 2nd and 3rd phosphate group

Enzymes

proteins that end in -ase that catalyze reactions by lowering activation energy

Enzyme-Substrate specificity

The structure of enzymes includes the active site which specifically interacts with substrate molecules (shape, size, charge)

Enzyme-substrate compatibility

the substrate’s charge and shape must be compatible with active site of enzyme

Enzyme-substrate complex

when both enzyme and substrate are together

Induced fit

enzymes modify shape of their active site to allow the substrate to bind better

Enzyme catabolism vs anabolism

substrate is broken down vs. substrates are built into complex molecules

3 factors that affect enzyme shape and thus function

temperature, pH, and chemical

Denaturation

when enzymes protein structure is disrupted —> can’t catalyze anymore or is less efficient

sometimes REVERSIBLE

The effect of heat on enzyme function

Increases rate of enzyme activity due to higher speed of movement and increased collision frequency between enzymes and substrates; then denatures at a point

The effect of pH on enzyme function

Causes hydrogen bonds in enzyme structure to break

Cofactors and Coenzymes

Cofactors: nonprotein molecules that assist enzyme function

Coenzymes: organic cofactors i.e. vitamins

Enzyme inhibition (2 types; not active/allosteric)

Permanent: inhibitor binds with covalent e.g. toxins

Reversible: inhibitor binds with weak interactions

The effect of relative substrate and product concentration on enzyme activity

Increased substrate concentration causes increased reaction rate (substrate saturation)

Increased product concentration can act as inhibitor to earlier enzymes in same pathway [FEEDBACK INHIBITION]

Competitive enzyme inhibitors

Binds to active site

Can be reversed with increased substrate concentrations to compete back!

Noncompetitive/Allosteric enzyme inhibitors

Binds to allosteric site, changing shape of active site and preventing substrate binding

Noncompetitive/Allosteric activators

Binds to allosteric site, stabilizes open active site

Allosteric cooperativity

Binds to active site, stabilizes other open active sites

Feedback inhibition

When the end product of metabolic pathway acts as inhibitor to early enzyme in the same pathway

Light reactions

1. Light hits thylakoid

2. Electrons get excited, PSII —> PS1

   1. ETC: water splits in PSII and donates e-

   2. Fall of electrons drives H+ into lumen against gradient (active transport)

3. O2 dissipates from water

4. H+ flows through ATP synthase to stroma to make ATP

5. NADP+ electron carrier gets them from splitting of water ETC and the H+ from outside (stroma), becoming NADPH

So reactants: light, H2O, NADP+

Products: NADPH, O2, and ATP

Light-independent reactions/Calvin Cycle

1. Carbon fixation (CO2 incorporated into calvin 1 at a time)

2. Reduction (ATP and NADPH donates e- to reduce to G3P)

3. Regeneration of RuBP

So reactants: ATP, NADPH, CO2

Products: ADP, NADP+, G3P (3-carbon sugar used to synthesize glucose)

Photorespiration (C3 Plants)

when plants close their stomata to stop water loss; O2 is fixated instead of CO2

C4 Plants, CAM Plants

Alternate method to carbon fixation: spatial separation (partial closing of stomata), temporal separation

Steps of Cellular Respiration

1. Glycolysis (cytosol = the goo)

2. Pyruvate oxidation/Krebs/Citric Acid cycle (mitochondrial matrix = the room)

3. Oxidative Phosphorylation (cristae = the folds)

   1. ETC (e- fall drives H+ gradient creation)

   2. Chemiosmosis (H+ flow to create ATP)

Glycolysis

In cytosol; glucose splits into 2 pyruvate

Reactants: glucose, ATP and ADP, NAD+

Products: pyruvate, net ATP, NADH and extra H+, H2O

Pyruvate oxidation/Krebs/Citric Acid cycle

In mitochondrial matrix; if oxygen present:

1. pyruvate oxidized into acetyl coA; creates acetyl coA, NADH, and CO2

2. acetyl coA converted into citrate; creates citrate, NADH, FADH2, and CO2

Reactants: acetyl coA —> citrate, NAD+

Products: NADH, FADH2, ATP, CO2

Oxidative Phosphorylation (ETC part)

In inner membrane/cristae;

1. NADH and FADH2 donate e-s to ETC from inner side and H+ to freely roam inside mitochondrial matrix

2. H+ + electrons all used up from the cycle + O2 produces water inside matrix

3. H+ pumped out into the inter membrane space

4. Flow back in so ATP synthase can create ATP inside matrix

Reactants: NADH, FADH2, O2

Products: NAD+, FADH, H2O, ATP

Cytoskeleton (Microtubules vs Microfilaments vs Intermediate filaments)

Microtubules: cell rigidity/structure; form mitotic spindle in cell division

Microfilaments/actin filaments: cell movement e.g. cytokinesis, muscle contraction

Intermediate filaments: anchor organelles in place

Respiration w/o oxygen

1. Anaerobic (w/ ETC)

2. Fermentation (w/o ETC) to produce ATP

   1. Alcohol (NAD+ reduced from glycolysis, directly donates e-s to acetaldehyde, forms ethanol waste)

   2. Lactic acid (NAD+ reduced from glycolysis, directly donates e-s to pyruvate, forms lactate waste)

3 Factors of Genetic diversity via Meiosis

1. Segregation (1 allele)

2. Independent assortment in metaphase 1

3. Random fertilization

Chromosome numbers throughout meiosis

1. Beginning: 2n chromosomes / 2n chromatids

2. After S phase: 2n chromosomes / 4n chromatids

3. After Meiosis 1: n chromosomes / 2n chromatids per daughter (2)

4. After Meiosis 2: n chromosomes / n chromatids per daughter (4)

True breeding

organisms that produce offspring of same variety

Chi square degrees of freedom

n-1 (for genotypes, n = alleles; for phenotypes, n = different phenotypes)

Chi Square

form of statistical test used to compare observed results with expected results

• whether data from experiment is a “good fit”

• if deviations from expected data are due to random chance or other circumstances

• testing the null

x²=sum of ((observed-expected results)²/expected)

Dihybrid cross phenotypic ratio

9:3:3:1

Law of segregation

Each gamete has only 1 allele for given trait (since meiosis divides homologous chromosomes)

Law of independent assortment

Genes for one trait aren’t necessarily inherited with genes for another (eye color and hair color are inherited differently)

A reason why laws of independent assortment/segregation aren’t working

Genes are probably are on the same chromosome and have lower recombination frequency (linked genes)

Pedigree tips

1. If trait is dominant, one parent must have trait

2. If trait is X-linked, males are more commonly affected than females

3. If genders are equally affected, probably autosomal

Monohybrid cross

BB x bb

Dihybrid cross

YYRR x yyrr

Nonmendelian genetics

• Traits have varying degrees of dominance (codominance or incomplete)

• multiple genes act on a trait (polygenic inheritance)

• sex-linked

• mitochondrial/chloroplast DNA

Incomplete dominance

red + white = pink flowers (neither allele fully dominant)

Codominance

2 alleles are both expressed

type AB blood = A + B

Multiple alleles

some genes exist in forms with more than two alleles

Epistasis

allele at 1 locus affects allele at another locus. it can mask the effect of another locus e.g. gene for pigment & gene for depositing pigment in hair; if second 1 is albino, then first gene for pigment does not matter.

Linked genes

genes located near each other on same chromosome that tend to inherit together

50% or higher recombination frequency

genes are far apart on same chromosome or on two different

If x² > critical value [from table]

There is a statistically significant difference between observed and expected (reject null!)

If x² < critical value [from table]

there is NOT a statistically significant difference between observed and expected (fail to reject—not accept—null!)

How to calculate map distance between genes

probability that they will segregate as a unit aka recombination frequency

• each % point = 1 map distance unit

• 50% or higher = located on different chromosomes or far apart on same; UNLINKED

Chloroplast and mitochondrial genes inheritance

randomly assorted to gametes and daughter cells (do not follow Mendelian rules)

• In animals, mitochondria = from egg so maternally

• In plants, mitochondria and chloroplasts = from ovule so maternally

Phenotypic plasticity

when a single genotype produces multiple phenotypes under different environmental conditions

e.g.

• height and weight in humans

• flower color based on soil pH

• seasonal fur color in arctic animals

• sex determination in reptiles

• Increased UV on melanin production in animals

• Presence of opposite mating type on pheromone production in yeast and other fungi

Example of genetic disorders

Aneuploidy (results from X-ray radiation):

• Nondisjunction (trisomy 21/down syndrome) when chromosome 21 doesn’t separate properly; extra chromosome

• Inversion: when segment of chromosome breaks and flips

• Deletion: when it breaks off

• Duplications: when it breaks off of one homologous chromosome and attaches to other so other has 2x gene

• Translocation: when it breaks off and attaches to a NON-homologous chromosome

Sickle cell anemia: autosomal recessive disease from mutated gene leads to abnormal hemoglobin

X-linked color blindness

Tay-Sachs disease: autosomal recessive disease from mutated gene

Niche partitioning

Decreased competition among species for a niche because they are accessing a resource in different ways

Trophic cascade

Negative effect of removing key species —> population growth change exponentially, interrupted energy flow and limit resource availability

Species richness vs. relative abundance

many different species vs. lots of individuals per species

Removal of keystone species

Ecosystem collapse because of disproportionate influence to their relative abundance in an ecosystem; prey increases in number and prey’s food populations decrease

More biodiversity for an ecosystem

More resilient

Polar water meaning

unequal electron sharing (O has partial negative, H have partial positive)

Hydrogen bonds in water are intermolecular or intramolecular

intermolecular

The strength of hydrogen bonds

weak compared to ionic/covalent

Water properties

1. Cohesion

   1. High heat of vaporization

   2. High specific heat

   3. Capillary action

   4. Surface tension

   5. Density of ice (less dense than liquid)

2. Adhesion

   1. Capillary action (plant xylem is polar so H2O can bind); when adhesion > cohesion

   2. Excellent solvency to polar molecules to which it can hydrogen-bond

Transpiration

Plant sweating, releasing water vapor from stomata which makes room for more water to go up

• Important for water cycle

Monomer of Protein

Amino acid

Amino Acid structure

central carbon, variable R side chain (20 diff kinds can be polar/nonpolar/ionic), amine group and carboxyl group on either side of carbon

Peptide bond

Primary structure bond which link amino acids together

Secondary structure

Beta sheets (pleated/folded paper) and alpha helices (corkscrew) because of hydrogen bonds between carbonyl and amine groups of amino acids

Tertiary structure

3D shapes; minimizes free energy

formed by R group interactions

• hydrogen bonds between polar R groups

• ionic bonds between charged side chains

• disulfide bridges (covalent) between sulfur from sulfhydryl (SH) group on cysteines

Quaternary protein structure

Multiple polypeptides interacting with each other; not for all proteins

Carboxyl group

COOH

Carbonyl group

CO

Hydroxyl group

OH

Carbohydrate monomer, dimer, polymer

1. Monosaccharide: glucose

2. Disaccharide: sucrose

3. Polysaccharide: storage (starch/glycogen), structure (cellulose/chitin)

Type of bonds in carbohydrates

Glycosidic bonds

Passive transport (2 types)

1. Simple diffusion (small non polar molecules or gases)

2. Facilitated diffusion (hydrophilic uncharged molecules and charged ions via transport proteins)

3. Osmosis

both are down concentration gradient / does not require ATP

Active Transport

Requires ATP, unfavorable movement can be coupled with favorable movement i.e. cotransport

1. Sodium/Potassium pump

2. ATP synthase

3. Endocytosis/exocytosis

5 carbon sugar types

1. Ribose (2 OHs)

2. Deoxyribose (1 OH, 1 H)

Chromosome numbers through mitosis

1. Beginning: 2n chromosomes / 2n chromatids

2. After S-phase: 2n chromosomes / 4n chromatids

3. After mitosis: 2n chromosomes / 2n chromatids per daughter (2)

Biotechnology (4 types)

Used to analyze and manipulate DNA/RNA

1. PCR (Polymerase Chain Reaction)

   1. DNA fragments are copied then amplified and even run through electrophoresis

   2. Used to identify organisms and perform phylogenetic analyses

2. Bacterial transformation

   1. Plasmids removed, gene of interest inserted, recombinant DNA reintroduced so gene expressed

3. DNA Sequencing

   1. Determines order of nucleotides in DNA molecule

4. Gel Electrophoresis

   1. Separates molecules according to size and charge

   2. DNA is negatively charged, so will move to + side and smaller will move faster

How endothermic organisms generate heat from cellular respiration

Decoupling oxidative phosphorylation from ETC generates heat, which can be used to regulate body temperature

• done by proteins allowing leakage of H+ across plasma membrane as heat

Prokaryotes’ chromosome

single, circular, double stranded chromosome in nucleoid

Eukaryotes vs prokaryotes vs plasmids chromosomal structure

Euk: multiple linear chromosomes
Prok: single circular chromosome

Plasmids: circular double-stranded (like mini-DNA)

Plasmids

Small double-stranded, circular DNA molecules in both prokaryotes and eukaryotes (double stranded because DNA, DNA because double stranded)

Purines

Double ring structure; Adenine and Guanine

Pyrimidines

Single ring structure; Cytosine, Uracil, and Thyamine

Direction DNA (replication) and RNA (transcription) are synthesized in

5’ to 3’

Semiconservative process

DNA replicated; one strand of DNA = template for new strand of complementary

Helicase

Unzipper of DNA in replication

Topoisomerase

Relaxes supercoiling in front of replication fork

Ligase

Joins Okazaki fragments on lagging strand

DNA polymerase

synthesizes DNA strands; requires RNA primers to initiate!!