bio exam

thermodynamics

chemistry that focuses on energy changes

energy

capacity to do work

what are the two states of energy

kinetic and potential

kinetic energy

energy of motion

potential energy

stored energy

how can we measure energy

heat

what does one calorie mean

heat needed to raise 1 g of water by 1 degree celsius

what are redox reactions

oxidation and reduction

oxidation

loss of electrons

reduction

gains an electron

what are the thermodynamic laws

1. energy can’t be made or destroyed

2. entropy/disorder is continuously increasing

free energy equation

G=H-TS

what does the G in the free equation mean

energy available for work

what does H in the free equation mean

enthalpy (energy in chemical bonds)

what does T in the free equation mean

absolute temp (C degrees + 273)

what does the S in the free equation mean

entropy

positive delta g reactions

products have more free energy than reactants and they’re not spontaneous

negative delta g reactions

products have less free energy than reactants and they’re spontaneous

endergonic

not spontaneous

exergonic

spontaneous

activation energy

extra energy that destabilizes existing bonds and initiates a chemical reaction

what does it mean when there is larger activation energy

there will be a slower reaction rate

how does the reaction rate increase

by heating it up or using a catalyst to lower the activation energy

catalysts

substances that influence chemical bonds to lower activation energy of a reaction

what can’t catalysts do

they can’t make endergonic into spontaneous and they can’t alter the proportion of reactants into a product

do exergonic or endergonic reactions need activation energy

exergonic

enzyme

a catalyst, can be proteins or RNA, can’t be changed or consumed, reusable, they specify cell structure and function, soluble, has an active site

active site

cleft/pocket for precise substrate binding, applies stress to distort bonds to lower activation energy

what factors influence enzyme function

temperature, pH, concentration of enzyme/ substrate, regulatory molecules

enzyme regulatory molecules

let cells control enzyme activities

inhibitors

molecules that bind to and decrease activity of an enzyme, it can be either competitive or non competitive

competitive inhibitor

competes with substrate for active site

non competitive inhibitor

binds to enzyme at another site other than the active site

allosteric site

a different site than the active site

metabolism

total of all chemical reactions done by an organism

anabolic

expend energy to synthesize molecules

catabolic

harvest energy by the breakdown of molecules

biochemical pathways

sequential, product of one reaction is the substrate for the next

autotrophs

make their own ATP from the sun

heterotrophs

live off the organic molecules made by autotrophs

how do cells make use of cellular respiration

extract energy from chemical bonds of organic molecules

what does cellular respiration involve

oxidation and dehydrogenation

parts of glucose oxidation

glycolysis, pyruvate oxidation, Krebs cycle, ETC and chemiosis

oxidative phosphorylation

10 NADH and 2 FADH2 go to ETC

where is chlorophyll located in

lumen

what are the 2 stages in photosynthesis

light dependent reactions and light independent reactions

light dependent reactions

need sunlight, occurs in thylakoid, make ATP, reduce NADP+ to NADPH, oxygen is the byproduct

light independent reactions

doesn’t need sunlight, occurs in stroma, uses ATP and NADPH to make organic molecules from carbon dioxide

photon

particle of light that contains energy

does a shorter wavelength mean more or less energy

more energy

chlorophyll a

main pigment in plants, absorbs violet blue and red light, only pigment that converts light to chemical

chlorophyll b

accessory pigment, absorbs blue and red orange light, adds range

carotenoids

accessory pigment, absorbs blue and green light, adds range, antioxidants

2 components in photosystem

antenna complex and reaction center

antenna complex

accessory pigment molecules gather photons and feed captured light energy to the reaction center

reaction center

1 or more chlorophyll a molecules pass excited electrons out of the photosystem to drive ATP/ organic molecule synthesis

3 parts of Calvin cycle

carbon fixation, reduction, and regeneration of RuBP

the 1’ is attached to

nitrogenous base

the 2’ is attached to

what determines if it’s RNA or DNA (OH or H)

the 3’ is attached to

the free OH

the 5’ is attached to

phosphate group

phosphodiester bonds

link nucleotides between 5’ to another 3’

how many H bonds does G have with C

3

how many H bonds does A have with T

2

what does DNA replication need

parental DNA molecule, DNA polymerase, and nucleoside triphosphate

DNA replication stages

initiation, elongation, termination

silent mutations

when one letter changes but it doesn’t make a difference in the outcome

missense mutations

changing a letter and getting a different protein

nonsense mutation

the changed letter leads to a stop codon

frame shift

when you lose a letter from one codon so the sequence shifts because the codons regroup

what are transcription factors

proteins on the DNA that give more control on where to transcribe

does RNA polymerase need a primer to start

no

DNA gyrase

relieves tension

Helicase

opens double helix

primase

makes RNA primer

what’s the Krebs cycle primary role

contribute electrons to electron carriers

what’s the first step in glycolysis

ATP is hydrolyzed into ADP

where does glycolysis happen

cytosol

where does the Krebs cycle and pyruvate oxidation happen

the matrix