AP Biology Unit 3

Metabolism

sum total of all chemical reactions in the body

bioluminescence

organisms converting energy into light

catabolic pathways

break down complex molecules into simpler compounds, releases energy (downhill)

anabolic pathways

build complicated molecules from simpler ones, consumes energy (uphill)

kinetic energy

motion energy

potential energy

resting energy

entropy

-measure of disorder

-energy is released as you move towards chaos

-naturally in nature we move towards chaos

thermodynamics

study of energy transformations

first law of thermodynamics

energy cannot be created or destroyed, only transferred and transformed

second law of thermodynamics

spontaneous changes that do not require outside energy increase the entropy, or disorder, of the universe

free energy

the energy available to do work

enthalpy

another term for heat

exergonic reaction

proceeds with a net release of free energy and in spontaneous and creates chaos

endergonic reaction

absorbs free energy from its surrounding and in nonspontaneous

mechanical, transport, chemical

cells three types of work

phosphorylation

moving a phos[hate from one molecule to another

dephosphorylation

taking away a phosphate

activation energy

the initial amount of energy needed for a reaction to occur

substrate

the reactant an enzyme acts on

active site

region where the substrate binds

cofactors

nonprotein enzyme helpers

coenzymes

organic cofactors

photoautotroph

organisms that use energy of sunlight to make organic molecules from water and carbon dioxide

photosynthesis

converts light energy to the chemical energy of food

stomata

openings on the backs of leaves for gas exchange

guard cells

controls what goes in and out of the stomata (stoma)

chloroplast

cell part that stores chrlorophyll

stroma

site of Calvin cycle

granumn (grana)

stacks of thylakoids

thylakoid

where light reaction occurs

lumen

hollow inside of thylakoid

competitive inhibitors

binds to active site of enzyme, competing with substrate

noncompetitive inhibitors

binds to another part of enzyme changing its function

allosteric regulation

shape

feedback inhibition

end product of metabolic pathway that shuts down the pathway

diatomic

element in nature found in pairs (oxygen)

cyclic electron flow

only photosystem I is used and only ATP is produced

ATP synthase

creates ATP

chlorophyll A

primary pigment

Chlorophyll B

accessory pigment

oxidation

losing electrons, more positive charge

reduction

gaining electrons, becoming more negative

photorespiration

O2 substitutes for CO2 in the active site of the enzyme rubisco, reducing the rate of photosynthesis

CAM plants

plants that store carbon dioxide to be released at night

C4 pathways

close guard whenever and stores carbon to be released

kinase

enzyme that moves phosphates

glycolysis

splitting of sugar, breaks down glucose into pyruvate, occurs in cytoplasm

oxidative phosphorylation

electron transport chain & chemiosmosis