ap biology | cellular energetics [UNFINISHED]

catalysts

speed up reactions

enzymes

biological catalysts

most enzymes are made of

proteins

ribozymes

enzymes made of rna

an enzyme’s active site interacts with the

substrate/reactant

the shape of an enzyme’s active state is

specific to the shape of the substrate

charges of r-groups of amino acids and active sites must

be compatible

denaturation

a change to the enzyme’s structure

often leads to severe loss or termination of function

what causes denaturation?

termperature and pH outside of the enzyme’s optimal range

competitive inhibators

similar in shape to substrates and compete for the active site

lowers the rate of enzyme-catalyzed reactions

non-competitive/allosteric inhibitors

bind to the allosteric site and changes the shape of the enzyme to not allow the substrate to bind at the active site

can adjust the rate of chemical reactions

cofactors

inorganic molecules that increase the efficiency of the reaction

bind to substrate or active site

coenzymes

organic molecules that increase the efficiency of the reaction

bind to substrate or active site

endergonic reactions

have products with a higher free energy level than its reactants

(considered energetically unfavorable)

exergonic reactions

have products with a lower free energy level than its reactants

(considered energetically favorable)

activation energy

the different between the energy level of the reactants and the transition state of the reaction

higher activation energies result in

slower chemical reactions

lower activation energies result in

faster chemical reactions

enzymes speed up chemical reactions by ____ the activation energy of the reaction

lowering

main ways an enzyme can lower the activation energy of a reaction

- bringing substrates together in the proper orientation for a reaction to occur

- destabilizing chemical bonds in the substrate by bending the substrate

- forming temporary ionic or covalent bonds with the substrate

enzymes ___ change an energetically unfavorable reaction into an energetically favorable reaction

cannot

coupled reactions

endergonic and exergonic reactions linked together

heterotrophs

organisms that consume other organisms to obtain organic molecules

autotrophs

organisms that can produce their own organic molecules from inorganic molecules

photoautotrophs

autotrophs that use light energy to power this process

photosynthesis equation

6CO2 + 6H2O →(light energy catalyst) C6H12O6 + 6O2

what’s the glucose formula?

C6H12O6

light-dependent reactions and light-independent reactions are

interdependent

what is a common synonym for light-independent reactions?

calvin cycle

adding substrate can mitigate the effects of ____ inhibators

competitive

enzymes are ____ consumed in the reactions they catalyze

never

the two main parts of photosynthesis

light-dependent reactions + light-independent reactions (calvin cycle)

light-dependent reactions

use energy from sunlight to split water, producing oygen gas, protons, and high-energy electrons

the protons and high-energy electrons are used to power the production of atp and nadph

the oxygen is released into the atmosphere while the atp and nadph are sent to the light-indpendent reactions

light-independent reactions (calvin cycle)

uses atp and nadph from light-dependent reactions and carbon dioxide to produce sugars

sends adp, p_i, and nadp+ back to the light-dependent reactions

where do light-indpendent reactions take place?

stroma

where do light-dpeendent reactions take place?

thylakoid

photosynthesis occurs in the

chloroplast

where does light-dependent reactions occur in prokaryotes?

infoldings of the plasma membrane

where does light-independent reactions occur in prokaryotes?

cytosol

photophosphorylation

when light energy is used to drive the production of atp

done by light exciting electrons to raise energy levels, releasing energy when electrons move through the chloroplast

nadp+ accepts these electrons at the end of light-dependent reactions, forming nadph

chloropyll

a light absorbing pigment that capture the energy of photons from the sun

found in photosystems I + ii

a photosystem is composed of

proteins, chlorophyll, and accessory pigments (other light-absorbing pigments)

electron transport chain

the area that uses carrier molecules to take electrons from photosystem ii to photosystem i

which photosystem comes first in light-dependent reactions?

photosystem ii

how does photosystem ii get its electrons?

photolysis

what occurs during photolysis?

water molecules are split, producing protons, electrons for photosystem ii, and oxygen gas

the protons will be used to form a gradient as electrons pass through the electron transport chain

atp synthase

an enzyme that produces ATP using the proton gradient generated by photolysis of water and the eletron transport chain

chemiosmosis

the process of using a proton gradient and atp synthase to produce atp

what happens to the electron that is now in photosystem i?

boosted by another photon to pass through a series of carriers along with a proton

transferred to nadp+ by the enzyme nadp+ reductase

the produces nadph

nadph

the final result of light-dependent reactions which will provide reducing power for the light-independent reactions

three main stages of light-independent reactions (calvin cycle)

1. fixation of carbon

   rubisco adds a carbon dioxide to RuBP which produces an unstable six-carbon intermediate that breaks into two three-carbon molecules

2. reduction

   atp and nadph from light dependent reactions are used to reduce the three-carbon molecule

   g3p is produced as a result

   1. regeneration of RuBP

      uses the atp from the light-dependent reactions to rearrange five g3p molecules and form three RuBP molecules

cellular respiration equation

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP

what are the four cellular processes of cellular respiration?

1. glycolysis

2. oxidation of pyruvate

3. krebs cycle (citric acid cycle)

4. oxidative phsophrylation

anaerobic

absence of oxygen

what cellular processes can be performed in anaerobic respiration?

glycolysis + fermentation

aerobic

requires oxygen

what cellular processes can be performed in aerobic respiration?

- glycolysis

- oxidation of pyruvate

- krebs cycle (citric acid cycle)

- oxidative phosphorylation

- fermentation

where does glycolysis occur?

in the cytosol

what evidence supports the theory that glycolysis was one of the first metabolic processes to evolve?

enzymes, which catalyze the