Cellular Energetics

Metabolism

Organisms chemical reactions

Emergent property

characteristic an entity gains when it becomes part of a bigger system

metabolic pathways

begins with one molecule ends with a product

catalyst

substance that increases the rate/speed of a reaction

Anabolic pathways

require energy to synthesize larger molecules from simpler ones

Catabolic pathways

release energy by breaking down complex molecules to simpler componds

cellular respiration

chemical process in which oxygen is used to make energy

Energy

capacity to cause change

Kinetic energy

energy of motion

Thermal energy

kinetic energy associated with random movement of atoms

Heat

Thermal energy in transfer from one object to another

Potential energy

energy that matter possesses because of its location

chemical energy

potential energy available for release in a chemical reaction

Thermodynamics

energy of transformation

isolated system

system that doesn’t interact with its surroundings

open system

system that interacts with its surrounding

first law of thermodynamics

energy can’t be created or destroyed

second law of thermodynamics

some energy is lost and unusable usually in the form of heat

entropy

measure of disorder

spontaneous process

occur without additional energy

free energy

measure of energy that is available to do work

exergonic reaction

spontaneous, energy released, chemical reaction where change in free energy is negative

endergonic reaction

nonspontaneous, energy required,

hydrolysis

chemical breakdown of a compound due to reaction with water.

catalyst

speeds up reaction, lowers activation energy

enzyme

biological catalysts by accelerating chemical reactions.

activation energy

initial energy needed to start a chemical reaction

substrate

a molecule upon which an enzyme acts.

enzyme substrate complex

enzyme binds to its substrate

active site

region where substrate binds

cofactors

non-protein chemical that assists with a biological chemical reaction

coenzyme

organic cofactor compounds required by many enzymes for catalytic activity.

competitive inhibitors

binds to the active site and prevents the substrate from binding there

noncompetitive inhibitors

bind to another partt of an enzyme, causing the enzyme to change shape and making the active site less effective

allosteric regulation

inhibit or stimulate an enzyme’s activity

feedback inhibition

end product of a metabolic pathway shuts down the pathway

catabolic

breakdown to release energy

anabolic

requires energy, build bonds

reduction

electrons added to a compond

oxidation

electrons lost

respiration

obtain energy by taking in oxygen

fermentation

anarobic, degradation of sugars without oxygen

glycolysis

breaks down glucose into 2 molecules of pyruvate

citric acid cycle

completes the breakdown of glucose

oxidative phosphorylation

The process by which ATP is formed as a result of the transfer of electrons from NADH and FADH₂ to O₂ by a series of electron carriers.

chemiosmosis

The movement of ions across a semipermeable membrane bound structure, down their electrochemical gradient

alcohol fermentation

pyruvate is converted to ethanol in two steps

lactic acid fermentation

pyruvate is reduced by NDH, forming lactate as an end product, with no release of CO2

obligate anaerobes

carry out fermentation or anaerobic respiration and cannot survive in presence of O2

facultative anaerobes

yeast and bacteria that can survive using fermentation or cellular respiration

beta oxidation

metabolic process involving multiple steps by which fatty acid molecules are broken down to produce energy.

Photosynthesis

process that converts solar energy into chemical energy

Autotrophs

sustain themselves without eating anything derived from other organisms

chlorophyll

green pigment in chloroplasts

mesophyll

interior tissue of the leaf

stomata

pores found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange.

thylakoids

membrane-bound compartments inside chloroplasts, site of the light-dependent reactions of photosynthesis.

stroma

colorless fluid surrounding the grana within the chloroplast.

calvin cycle

the cycle of enzyme-catalyzed dark reactions of photosynthesis that occurs in the chloroplasts of plants and in many bacteria and that involves the fixation of carbon dioxide and the formation of a 6-carbon sugar.

photophosphorylation

generate atp from adp by adding phosphate group

carbon fixation

the process by which CO2 is incorporated into organic compounds.

carotenoids

absorb excessive light that would damage chlorophyll

Photosystem ll

functions first ATP synthesis and hydrolysis of water

Photosystem l

Happens second, NADPH synthesis