bio189 exam 2

chapters 4,6,23, and 27

autotroph

organisms that make their own food

heterotroph

organisms that must obtain energy by consuming other organisms

kinetic energy

energy associated with motion (moving)

potential energy

stored energy resulting from position, structure, or chemical bond arrangement (could move)

first law of thermodynamics

energy can only be transformed, it can NOT be created nor destroyed

entropy

measure of the amount of “disorder” in a given system (randomness)

high entropy

higher temperature → higher entropy (particles have more energy, move faster, spread out more)

low entropy

low temperature → low entropy (particles have less energy, move slower, stay more together)

light energy

energy that comes from light (sun, light bulb, flashlight)

thermal energy

energy from heat (fire, hot stove)

electrical energy

energy from moving electricity/charged particles (when electrons move, charging your phone)

chemical energy

energy stored inside chemical bonds (food, batteries, gasoline)

ATP stores

chemical potential energy (glucose)

energy transformation

light → plant → glucose → ATP → cellular work

entropy example

clean room → things get messy → messy room → more disorder (messy room has higher entropy)

thermodynamics

the study of energy and how energy changes and moves

second law of thermodynamics

the total entropy of the universe tends to increase (energy naturally spreads out)

entropy and chemical reactions

entropy measures how measures how spread out and random things are, and chemical reactions can increase or decrease entropy as molecules and energy are rearranged

4 small molecules → 1 large molecule

entropy decreases because several molecules are being organized into one larger molecule

anabolism

builds molecules, small → large, usually requires energy, “build”

catabolism

breaks molecules, large → small, usually releases energy, “break”

anabolism example

A + B → AB

catabolism example

AB → A + B

endergonic

needs energy added to it (cannot happen without an energy input)

exergonic

releases energy (has energy available to release) (exit)

exergonic example

breaking down glucose

endergonic example

plants use light energy to make glucose

oxidation reduction (redox) reaction diagraph

redox reaction

when one atom gives away electrons and another atom takes them (ex: passing a ball)

oxidation

loses electron

reduction

gains electron

reaction coupling

a cell uses energy released from one reaction to power another reaction that requires energy

ATP (adenosine triphosphate) definition

the cell’s main short term energy carrier

ATP stores:

energy short term

ATP contains:

adenine, ribose, 3 phosphate groups

adenine

nitrogen containing base

ribose

5 carbon sugar

3 phosphate groups

where energy is associated

how many phosphates does ATP have

3 phosphates

how many phosphates does ADP have

2 phosphates

exergonic ΔG

negative

endergonic ΔG

positive

enzyme characteristics

• speeds up reactions

• can be used again

• works with specific molecules

• can be affected by temperature and pH

enzyme

helper

substrate

the molecule an enzyme works on

active site

when the substrate attaches

activation energy

energy needed to START a reaction

without enzyme

big hill

with enzyme

smaller hill

enzyme’s job

lowers activiation energy

metabolic pathway

bunch of reactions that happen one after another

pathway

steps

competitive inhibition

an inhibitor tries to take the active site (substrate and inhibitor compete for the same spot

noncompetitive inhibition

the inhibitor attaches to a different spot on the enzyme

feedback inhibition

final product stops an earlier stop

allosteric regulation

binds somewhere else and changes the enzyme, can turn activity up or down

cellular transport

how substances move into and out of a cell

what does the plasma membrane control

what enters and leaves

passive transport

does not use ATP (energy) (high concentration → low concentration)

active transport

uses ATP (energy) (low concentration → high concentration)

simple diffusion

no ATP, high → low, protein needed

facilitated diffusion

no ATP, high → low, protein (helped)

osmosis

movement of water across a membrane, no ATP (water follows solute)

endocytosis

ATP, into cell (enter)

exocytosis

ATP, out of cell (end)

tonicity

describes how the solution outside the cell affects water movement

• hypotonic

• hypertonic

• isotonic

hypotonic

low solute outside the cell

• water moves outside → into cell

• water enters → cell swells → may burst

• water goes in

hypertonic

high solute outside the cell

• water moves cell → outside

• water leaves → cell shrivels

• water goes out

isotonic

solute concentration is approximately equal inside and outside

• water moves both ways equally

• no net water movement

• cells stays about the same size

hypo

water goes IN → cell gets BIG

hyper

water goes OUT → cell gets SMALL

anabolism

• builds large molecules

• small → big

• requires energy

• ex: photosynthesis

catabolism

• breaks down larger molecules

• big → small

• releases energy

• ex: cellular respiration

photosynthesis

• builds glucose

• anabolic

• energy goes in

photosynthesis formula

CO2 + H2O + light → glucose + O2

cellular respiration

• breaks down glucose

• catabolic

• energy comes OUT

cellular respiration formula

glucose + O2 → CO2 + H2O + ATP

free energy graph: photosynthesis

• requires energy

• endergonic

• anabolic

free energy graph: cellular respiration

• releases energy

• exergonic

• catabolic

photosynthesis reaction

6CO2 + 6H2O + light energy → C6H12O6 + 6O2

creating glucose

cellular respiration reaction

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP

glucose being broken down

glycolysis

• happens in the cytoplasm

• breaks glucose → pyruvate

• produces some ATP and NADH

pyruvate oxidation

• pyruvate is converted into acetyl-CoA

• produces NADH and releases CO2

Krebs Cycle (citric acid cycle)

• breaks down acetyl-CoA

• produces ATP, NADH, and FADH2

• Releases CO2

electron transport system (ets)

• uses electrons from NADH and FADH2

• produces most of the ATP

• o2 is the final electron acceptor

• produces h2o

easy way to remember the stages of cellular respiration

G → P → K →E

glycolysis → pyruvate oxidation → krebs cycle → electron transport

big picture of cellular respiration

glucose → pyruvate → acetyl-CoA → krebs cycle → ETS → lots of ATP

mitochondrial matrix

• inside of the mitochondrion

• krebs cycle happens here

• pyruvate oxidation also happens here

• matrix = krebs

inner mitochondrial membrane

• folded membrane inside the mitochondrion

• ETC is located here

• where most of ATP is made

• folds are called cristae

• inner membrane = ETC

cristae

• folds of the inner membrane

• increase the surface area for ETC

• more surface area = more room for ATP-producing machinery

intermembrane space

• the space between the outer and inner membranes

• during the ETC, H+ ions build up here

• creates a gradient that helps make ATP

memory : matrix

krebs

memory : inner membrane

ETC

memory : intermembrane space

H’ builds up

memory : cristae

folds that give more space for ETC

mitochondrion big picture

glucose → glycolysis → pyruvate → matrix → krebs → inner membrane/etc → lots of atp

ATP synthase

• ETC pumps H+ ions into the intermembrane space

• creates a buildup of H+

• H+ wants to flow back into the matrix

• H+ flows thru ATP synthase

• flow provides the energy to make ATP

glycolysis

splitting glucose

• does not require oxygen directly

glycolysis make up

• starts with 1 glucose

• ends with 2 pyruvate

glycolysis produces:

• 2 ATP net

• 2 NADH

• 2 pyruvate