AP Biology Midterm Study Guide

AP Biology Mid-Term Study Guide 2015
Monitha Patel

Chemical Bonding
Compounds
Sharing of a pair of valence electrons by two or more different atoms
Molecule
Two or more atoms held together by covalent bonds
Ionic
Electron attraction between two atoms
Cations (+1) and Anions (-1) attract
Covalent
Sharing of valance electrons between atoms
Nonpolar
Electrons are shared equally
O2
Polar Covalent
Unequal sharing of electrons between atoms
Two hydrogen atoms are bonded to a single oxygen atom
Hydrogen
Hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom
Attraction of water molecules to one another
Slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule
Moles
Divide for litersgrams
1 Mol per ml/ liters
1 mole of anything=6.02x1023
Gibbs Free Energy

Endergonic reaction
Absorbs energy
(+
Exergonic
Spontaneous and released energy
(-)
ATP Hydrolysis (Exergonic reaction)
Phosphate group leaves ATP ADP
Energy is released pH Scale
0-6.9: Acidic [H+ ]>[OH- ]
7=Neutral [H+ ]=[OH- ]
7.1-14-Basic [H+ ]<[OH- ]
Buffers maintain pH
Cell membrane
Cell membrane
Phospholipids and proteins
Factors that affect permeability
Polarity – net charge
Cannot get across easily
Ions –Hydrophilic
Hydrophobic cores restricts polar molecules
Permeable to…
Small and hydrophobic (nonpolar) molecules
Regulation of permeability
Facilitated diffusion
Proteins transports: Channel and carrier proteins
Active transport
Uses energy across gradient
Phosphorylation of Na+/K+ protein pump
Activated by the transfer of phosphate group to a transport protein
High K inside and high Na outside pump balances the two concentrations
Osmosis
Hypertonic
Doesn’t allow solutes
Looses watercell shrivels
Hypotonic
Gains waterswell and lyse (burst)
Water potential Solute potential Amino acids
20 amino acids
Polypeptides
Polymers of amino acids
Makes up a protein
Carboxyl and amino acid groups
A(alpha)-carbon
Asymmetric center carbon atom
Side chain
Determines type of amino acid
Nonpolar side chains
Hydrophobic
Polar side chains
Hydrophilic
Joined by dehydration of a water molecule
Primary
Peptide bonds are created
A chain of linked amino acids
Not affected by hydrogen bonding
Secondary
Hydrogen bonds between one amino acid group of a peptide and carboxyl group of another
A helix and b pleated sheet
Coils and folds
Tertiary structure
3-D shape of a fully folded polypeptide
Interactions between side chains (R-Groups)
Hydrophobic interactions
Quaternary
Overall protein structure by the bonding of polypeptides
Hemoglobin
Enzymes
Activation energy
Lowered to speed up a chemical reaction
Thermodynamic barrier that must be overcome by reactants to form a product

A+B C+D
Exergonic

Allosteric regulation
Regulatory molecules that change shape and function of active site
Bind to a site somewhere else on the molecule
Proteins function on one site affect binding of a regulatory molecule on another site
Can be inhibiting or stimulus
Associated with an enzyme with more than one subunit
Nucleotides
Nitrogenous base, phosphate group and pentose sugar
DNA vs RNA
DNA nucleotides contain different sugar than RNA
DNA: one less oxygen atom
Basic cellular organelles
Centrosomes- absent in plant cells
Smooth ER: produces oils, phospholipids, and organelles
Lysosomes: Contains hydrolysis enzymes
Vacuole: Takes up much of the volume of a plant cell
Mitochondria: ATP synthesis and contains its own DNA and ribosomes
Chloroplasts: Thylakoids, DNA, and ribosomes
Plastids: plant cells only
Prokaryotic Vs. Eukaryotic
Prokaryotic
No ER, mitochondria, nuclear envelope
ATP synthesis: Plasma membrane
Ribosome- present
Cellular respiration
Oxidization
Loosing an electron
Oxidizing agent
Gains electrons
Reduced
Gaining electron
Reducing agent
Looses electrons and potential energy
Glucosepyruvate
NADNADH
Travel of electrons: Foodglycolysiscitric acid cycleNADHATP
Glycolysis
Substrate level phosphorylation produces ATP
NAD is reduced to NADH
Each molecule of glucose = 2 ATP are used and 4 are produced
End products: NADH, pyruvate (full of free energy), and ATP
Cytosol
No O2Fermentation Electron Transport Chain –pH of matrix increases
FADH2 donates its electrons to the ETC (oxidative)
Consumed oxygen
Accepts electrons
Mitochondrial inner membrane: Transport proteins
Protein gradient across membrane supplies ATP
H+ are pumped into the inner membrane of mitochondria

Starts with NADH, FADH2, and O2
Each electron carrier alternates of being reduced and oxidized
Complex IV transports electrons to O2
4 electron combine with O2 and 4 protons

ATP Synthase
H+ across membrane spins the turbine
Chemiosmosis
Oxidative phosphorylation
Produces the most ATP when glucose is oxidized to CO2 and water
Cell communication
Reception
G-protein coupled receptor GTP
Activates/inactivates g-protein
GTPase activity
Hydrolyzes GTP binding to G protein
G-protein binds to enzyme and triggers reaction
G protein is bound to GDP again

Transduction
Cascade effect that amplifies original signal manifold
G-protein signal transduction pathway
EpinephrineG protein-coupled receptorG proteinadenylyl cyclasecAMP
Second messenger: cAMP
Meiosis
Prophase I
Centrioles move apart
Crossing over
Metaphase
Chromosomes come together –metaphase plate
Telophase
Chromatidschromosomes

I : G1
II: DNA synthesis: Chromosomes are replicated III: Metaphase
IV: Mitosis
V: G1

Mitosis Vs Meiosis

Mitosis and meiosis
Separation of sister chromatids in anaphase
Mitosis
Metaphase: karyotype
Meiosis I only
Produces 2 genetically different daughter cells
Independent assortment
Homologous chromosomes move to opposite poles

I=Anaphase I
V=Anaphase II

Genetics

Human blood type
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r, respectively. A third gene for the MN blood group has codominant alleles M and N.
Partial Possible genotype for son : IBi
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r, respectively. A third gene for the MN blood group has codominant alleles M and N.
Possible mother genotype: IAi
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r, respectively. A third gene for the MN blood group has codominant alleles M and N.
Phenotype for father : B positive
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r, respectively. A third gene for the MN blood group has codominant alleles M and N.
Each parent is either M or MN

Law of segregation Anaphase I
Law of independent assortment
Two or more genes relative to one another
Alignments of tetrads at equator
Laws of inheritance
Mendelian genes are at specific loci on the chromosome and it turns segregation during meiosis
Repressors
Repressible operon
Metabolite binds to the repressor protein and inactivate it
CoRepressor
Turns off genes
Repressor
Produced by regulatory gene
Active =Stops transcription
Inducer
Binds to repressor so repressor can’t bind to operator
Trp operon (repressible operon)
Turned off whenever tryptophan is added to growth medium
Lac operon
Allolactose
When lactose enters the cell
Allolatose binds to repressor protein
Transcribed
Cyclic APM and lactose levels are high within the cell
Gene expression
Histone acetylation
Loosens chromatin structure to permit transcription
Tumor suppressor genes
Benign vs malignant tumor
Proto-oncogenes
Code for proteins associated with cell growth
Tumor suppressor genes
Encode proteins that promote DNA repair or cell-cell adhesion
Ras protein and tumors cause growth factor signaling to be hyperactive

Restriction Enzymes
Sticky ends- promotes variation
DNA Finger printing
Number of repeats varies widely from person to person
Complementary DNA (cDNA)
Made from reverse transcriptase
Protein synthesis regulation
Degradation
Ubiquitin – protein destruction
Regulatory proteins are activated/inactived block transcription (protein synthesis)
Cancer
Regulation is lost
Genomics
Single nucleotide polymorphisms (SNPS)
Variation
Different DNA building blocks that can be substituted
Cells
Larger cell (same shape of a smaller cell)
Less surface area per unit of volume