AP Biology - Unit 3

Key properties of enzymes

proteins that catalyze reactions in cells, lower activation energy, increase rate of reactions.

changing this effects enzymes

temperature, pH, ion concentration, interferes with bonds which change active site

denaturation

loss of normal shape of a protein

more kinetic energy increases molecular motion which..

increases chance that enzymes will bind with substrate

reversible denaturation

restoration of optical conditions restores the enzymes function as it regains optimal shape

irreversible denaturation

enzymes shape is permanently changes and its catalytic ability is destroyed

Low substrate concentration

the probability of the enzyme meeting it substrate is low and the product is produced at a very low rate

medium substrate concentration

the reaction rate increased, collision rate increased

high substrate concentration

you get to a saturation point and all enzymes have active sites interacting with substrate, rate peaks

competitive inhibition

foreign molecule blocking enzymes active site, keeps from binding, inhibits rate of reaction

non competitive

foreign molecule binds away from active site at a allosterice site, causes ripple effect which causes a change in the active site so substrate can not bind.

metabolic pathway

linked series of enzyme catalyzed chemical reactions occurring within a cell, can be linear or circle

autotrophs

organisms that can produce their own food, plants

chemoautotrophs

the energy for their life process comes from chemo synthesis.

chemosynthesis

oxidizing inorganic substances like iron, sulfur, or hydrogen sulfide.

heterotrophs

capture the energy present in organic compounds produced by other organisms, animals

exergonic reactions

release energy and increase entropy, energy of reactants is less than energy of products

entropy

how spread out energy is, higher =harder to get work from it

Endergonic reactions

require energy and decrease entropy, ex photosynthesis

ATP is used to

power work within cells, no sharing ATP between cells

to store energy cells must

take energy from food via cellular respiration or light and use it to make ATP from ADP and P

to release energy for work cells must

remove a phosphate group from ATP which creates ADP and P

energy coupling

linking an exergonic reaction to an endergonic one, provides energy to drive the endergonic reaction forward

formula for photosynthesis

6CO2+6H2O+light energy --> C6H12O6+6O2

the two phases of photosynthesis

light dependent and light independent (calvin cycle) reactions

light reactions

convert light energy into chemical energy (ATP)

calvin cycle

converts chemical energy in ATP and NADPH into carbohydrates which "fixes" carbon dioxide into high energy sugars

Chlorophyll function

the pigments that absorbs light energy in plant, absorbs most blue and red light and least green light

absorption spectrum

shows the amount of light absorbed at different light wavelengths

action spectrum

shows how various light wave length drive photosynthesis

thylakoids

membrane bound sacs, contain membrane bound photosystems and chlorophyll for light reactions, organized into stacks called grana

stroma

the cytoplasm of the chloroplast

phase 1 of calvin cycle; carbon fixation phase

carbon dioxide gas is brought into the biosphere

Phase 2 of calvin cycle; energy investment and harvest phase

matter is pulled out and becomes part of the plant and part of you

phase 3 of clavin cycle; regeneration of RuBp

the regeneration of the starting compound.

how light dependent reaction gets light

thylakoids absorb it

formula for cellular respiration

C6H12+6O2-> 6 CO2+6 H2O+ Energy (Heat+ATP)

the three steps of cellular respiration

glycolysis, krebs cycle, electron transport chain

what glycolysis does

glucose is broken down to form 2 molecules of pyruvate, glucose is oxidized (loses electrons) and 2 ATP are generated

what the krebs cycle does

pyruvate enters the mitochondria where its further oxidized to yield intermediate molecules, oxidaion of intermediate is completed, extracted electrons are picked up again by NAD+ to form NADH and another FAD to form FADH2

what the electron transport chain does

series of proteins embedded in inner mitochondrial membrane, provides energy needed to provide energy for active transport and chemical reactions