ap exam Flashcards
hydroxyl group
OH
carbonyl group
C - - O
carboxyl group
COOH
macromolecule types
carbohydrates- monosaccharides, polysaccharides; CHO
lipids- glycerol fatty acids, no polymers; CHOP
nucleic acids- nucleotides, DNA and RNA; CHONP
proteins- amino acids, polypeptides; CHONS
groups in carbohydrates
carbonyl group and hydroxyl groups
storage polysaccharides
plants store starch; animals store glycogen
structural polysaccharides
cellulose: tough substance that forms cell walls
chitin: forms exoskeleton of arthropods
amino acid groups
amino group, carboxyl group, variable side chain (R)
*side chains interact to determine shape and function of proteins
nucleotide parts
nitrogenous base (either pyrimidines or purines), five carbon sugar, phosphate group
nucleus
contains chromosomes
nucleolus is dense region where rRNA is synthesized
ER
synthesize membranes
compartmentalize cell
lysosomes
hydrolyze macromolecules and recycle cell materials
peroxisomes
catalyze reactions that produce H2O2
cytoskeleton
anchor organelles
allow for movement of vesicles and organelles and/or the whole cell
passive transport examples
diffusion
osmosis
facilitated diffusion
active transport examples
pumps
contransport
exocytosis
endocytosis
catabolic vs anabolic pathways
catabolic: pathways that release energy by breaking down complex molecules into simpler compounds
anabolic: pathways that consume energy to build complicated molecules from simpler molecules
induced fit
enzymes will change the shape of their active site to allow the substrate to bind better
enzyme catabolism
enzyme helps break down complex molcules
enzyme anabolism
enzyme helps build complex molecules
optimal conditions
higher temps and certain pH allow for enzymes to function optimally
cofactors vs inhibitors
cofactors are non protein molecules that assist in enzyme function (coenzymes are organic cofactors)
inhibitors reduce the activity of a certain enzyme (competitive, non competitive,
photosynthesis
location is chloroplast
stomata are pores in leaves that allow CO2 and O2 out
stroma is fluid, thylakoids are stacks of grana, chlorophyll is green pigment in thylakoid membranes
6CO2+6H2O+energy—> C6H12O6+6O2
stages: light reactions and calvin cycle
light reactions
occur in thylakoid membrane; converts solar energy to chemical energy (NADPH and ATP)
chlorophyll absorbs photon of light and electron is boosted to excited attar so realized energy and this repeats until it reaches P680 pair of chlorophyll a molecules and electron is transferred to primary electron acceptor; H2O had been split into two electrons, two H+, and an O
excited electrons pass to PS I via electron transport chain
fallen electron make energy for ATP; ATP synthase uses H+ to make ATP
in PS I light energy excited electrons to P700 and electron go down second electron transport chain; NADP+ reductive ctalyzes transfer of electrons from Fd to NADP+; plus H+ to make NADPH
makes O2, ATP, and NADPH
calvin cycle
uses ATP and NADH to reduce CO2 to sugar (G3P); synthesis of one G3P needs cycle three times
carbon fixation:
CO2 is attached to RuBP to form 3-phosphoglycerate
reduction:
3-phosphglucerate is phosphorylated by ATP and becomes 1,3-phosphoglyceeate; NADPH donate electrons to 1,3-phosphoglycerate and reduces it to G3P; six G3P are formed but only one is net gain
regeneration of RuBP:
other five G3P are used to regenerate three RuBP; cycle is ready to take in CO2 again
makes G3P, ADP, NADP+
C4 and CAM plants
C4: stomata partially close to conserve water
CAM: open stomata at night and close during day
cellular respiration
C6H12O6+6O2—>6CO2+6H2O
glycolysis:
occurs in cytosol
splits glucose (6C) into 2 pyruvates (3C)
pyruvate oxidation:
if oxygen is present, pyruvate enters mitochondria; pyruvates is oxidized into acetyl coA; CO2 and NADH produced
citric acid cycle/krebs cycle:
occurs in mitochondrial matrix
turns acetyl CoA into citrate and releases CO2; also produces ATP; electrons transferred to NADH and FADH2
oxidative phosphorylation:
consists of ETC and chemiosmosis
ETC is located in inner membrane of mitochondria; as electrons fall, proteins alternate between reduced and oxidized state; final electron acceptor is oxygen; H+/proton gradient created as proteins shuttle electrons and pump H+. chemiosmosis involves ATP synthase so as H+ flow though ATP is synthesized
anaerobic respiration
generates ATP using ETC in absence of oxygen
happens to prokaryotes and final electron acceptors are sulfates or nitrates
fermentation
generates ATP without ETC
extension of glycolysis by recycling NAD+
ways of cell contact
direct contact
local signaling
long-distance signaling
cell signaling stages
reception: ligand binds to receptor
transduction: signal is converted
response: cell response is offered
types of receptors
plasma membrane (G protein coupled receptors and ligand-gated ion channels) intracellular
signal transduction pathway regulation
phosphorylation by protein kinase and dephosphorylation by protein phosphotase
organization of DNA
before cell division cells must organize and package their DNA
DNA wraps around his tone proteins to form nucleosides that form chromatic which condense into chromosomes
centromere: region on each sister chromatid where they are most closely attached
kinetochore: proteins attached to centromere that link each sister chromatid to mitotic spindle
types of chromosomes
autosome and sex chromosomes
main sources of genetic variation in meiosis
synapsis/crossing over: homologous chromosomes pair up and connect to form a tetrad and DNA is exchanged
independent orientation (metaphase I); tetrads line up at metaphase plate
random fertilization: any sperm can fertilize any egg
epistasis
phenotypic expression of gene atone locus affects gene at another locus
polygenic inheritance
effect of two or more genes acting on a single phenotype
DNA structure
backbone made of sugar-phosphate and center made of nucleotide pairings
DNA replication
helipads separates DNA, single strand binding proteins prevent and topoisomerase DNA from resisting being unwinded
primase adds RNA primers then DNAP III adds DNA bases; on lagging strand, okazaki fragments are DNA added by DNAP III
DNAP I fills in gaps of where RNA primers have been removed by adding DNA
ligase seals up fragments in both strands
since there is no way to finish replication on the 5’ end of the lagging strand because DNAP III can only add nucleotides on the 3’ end, DNA would become shorter over generations. what prevents this?
telomerase adds telomeres that do not code for genes but are repeating units of short nucleotide sequences
transcription steps
initiation: RNA polymerase attaches to a promoter region of DNA
elongation: RNA polymerase opens up DNA and reads the triplet code of the template strand; pairs complementary RNA nucleotides
termination: RNA polymerase transcribes sequence of DNA called the polyadenylation signal sequence
pre-mRNA modifications
5’ cap: 5’ end of pre-mRNA receives a modified cap
poly-A tail: 3’ end of pre-mRNA receives adenine nucleotides
RNA splicing: sections of pre-mRNA called introns are removed and then exons are joined together so a single gene can code for more than one kind of polypeptide
sites of large subunit of ribosome
amino acid site, polypeptide site, exit site
steps of translation
initiation: small ribsomal subunit binds to mRNA and charged tRNA binds to start codon on mRNA
elongation: tRNA comes into A site and mRNA is moved through ribosome and it’s codons are read; tRNA moves to P site tRNA in P site goes to E site
termination: stope codon in mRNA reaches A site
genetic drift
chance events that cause a change in allele frequency’s from one generation to the next
bottleneck effect
founder effect
modes of natural selection
directional selection
stabilizing selection
dispersive selection
comparative morphology and homology
comparative morphology: analysis of the structures of living and extinct organisms
homology: characteristics in related species that
types of homology
embryonic homology: many species have similar embryonic development
vestigial structures: structures that are conserved even though they no longer have a use
molecular homology: many species share similar DNA and amino acid sequences
homologous structures
characteristics that are similar in two species because they share a common ancestor
convergent evolution
similar adaptations that have evolved in distantly related organisms due to similar environments
analogous structures
structures that are similar but have separate evolutionary origins
modes of speciation
allopathic speciation: physical barrier divides population or small population is separated from main population; populations are geographically isolated so prevents gene flow and likely caused by natural disasters
sympatric speciation: new species evolved while still inhabiting same geographic region as ancestral species; usually due to exploitation of a new niche
speciation occurs because of reproductive isolation; two types of reproductive isolation are
prezygotic barriers: prevent mating or hinder fertilization (habitat, temporal, behavioral, mechanical, or gametic isolation)
postzygotic barriers:: prevent hybrid zygote from developing into a viable and fertile adult (reduced hybrid viability, reduced hybrid fertility, hybrid breakdown)
paces of speciation
punctuated equilibrium: when evolution occurs rapidly after a long period of stasis
gradualism: when evolution occurs slowly over many years
types of evolution/speciation
divergent evolution
adaptive radiation
convergent evolution
RNA world hypothesis
proposes RNA could have been earliest genetic mayerial
innate behaviors
fixed action patterns: sequence of unlearned acts directly linked to a stimulus
migration
signal: stimulus generated and transmitted from one animal to another
directed movements: movements toward or away from a stimulus
learned behaviors
imprinting: long-lasting behavioral response to an individual
spatial learning: establishing memories based upon spatial structure of animal’s surroundings
associative learning: ability to associate one environmental feature with another
social learning: learning through observations and imitations of observed behaviors
responses in plants
phototropism: directional response that allows plants to grow towards light
photoperiodism: allows plants to develop in response to day length; plants flower only at certain times
physical and chemical defenses against herbavory
pH of soil affects plants
interspecific interactions
competition predation herbivory symbiosis facilitation
what is species diversity dependent on?
species richness and relative abundance
keystone species
not usually abundant, but other species in an ecosystem rely on them because of their important ecological niches
disturbances
ecological succession: gradual process by which the species composition of a community changes and develops over time after a disturbancd
main threats to biodiversity
habitat loss
invasive species
over harvesting
global change
biogeographical factors
large scale factors that contribute to a range of diversity observed
latitude: species are more diverse in tropics than at poles due to climate
area: larger areas are more diverse because they offer greater diversity of habitats
