Unit 2

Question 1

metabolism

Answer 1

sum of all chemical reactions that occur in the cell

anabolism + catabolism

Question 2

metabolic pathway

Answer 2

a sequential series of chemical reactions in living cells; each reaction is catalyzed by a unique enzyme

Question 3

anabolism

Answer 3

process of using energy to build large molecules from smaller molecules
ex. photosynthesis, synthesis of macromolecules

Question 4

catabolism

Answer 4

process of breaking down compounds into smaller molecules to release energy
ex. cellular respiration

Question 5

energy

Answer 5

the ability to do work

Question 6

kinetic energy vs potential energy

Answer 6

energy of motion vs stored energy

Question 7

when energy is transferred from one place to another, that is called _____

Answer 7

work

Question 8

1st law of thermodynamics

Answer 8

energy cannot be created or destroyed, but it can be transformed from one type into another and transferred from one object to another

all energy is accounted for

energy cannot be lost or disappear

Question 9

chemical energy

Answer 9

potential energy stored in the arrangement of the bonds in a compound

Question 10

bond energy

Answer 10

measure of the strength or stability of a covalent bond
equal to the minimum amount of energy required to break a particular type of bond
equal to the amount of energy released per mole when a bond is formed

Question 11

why do free, unbonded atoms have more chemical energy than any compound

Answer 11

because energy is always released when a bond forms

Question 12

2nd law of thermodynamics

Answer 12

the law of entropy
the entropy of the universe increases with any change that occurs
in every energy transfer or conversion, some of the useful energy in the system becomes unavailable to do work

Question 13

entropy

Answer 13

measure of disorder

Question 14

free energy

Answer 14

energy transformations are never 100% efficient. some energy is always lost to the environment, which leads to an increase in entropy.
energy that is not lost, or the portion left that is available to do (useful) work in the given system is free energy.

Question 15

how are changes in free energy produced

Answer 15

chemical reactions break some bonds and form new ones in products

Question 16

exergonic reactions

Answer 16

chemical reaction that releases energy
spontaneous and involves a decrease in free energy
products of reaction contain less free energy than reactants (delta G is negative)

Question 17

endergonic reactions

Answer 17

chemical reaction that requires energy
not spontaneous, and involves an increase in free energy, gains free energy
products of reaction contain more free energy than reactants (delta G is positive)

Question 18

adenosine triphosphate (ATP)

Answer 18

adenine, phosphate, 3 phosphate groups
last phosphate is unstable
large quantity of energy is released when ATP becomes ADP plus inorganic phosphate P

Question 19

redox reactions, electron transfers

Answer 19

transfer of electrons/ redox reactions during chemical reactions releases energy stored in organic molecules which is used to synthesize ATP

Question 20

oxidation vs reduction

Answer 20

loss of electrons from one substance vs addition of electrons to another substance

Question 21

the ______ form of a molecule is always at a higher energy level than the _________ form
and why

Answer 21

reduced, oxidized

because electrons that pass from one atom to another carry energy with them

Question 22

electron carriers

Answer 22

compounds that pick up electrons from energy-rich compounds and then donate them to low-energy compounds
an electron carrier is recycled

Question 23

all organisms require energy for

Answer 23

active transport
cell division
movement
production of biomolecules
reproduction
temperature regulation

Question 24

how does ATP store energy

Answer 24

a lot of stored energy in each bond

bonding of negative P groups is unstable > spring loaded > P groups “pop off” easily & release energy

Question 25

why is ATP unstoreable

Answer 25

too reactive transfers P too easily only short term storage

Question 26

digest organic molecules to get...

Answer 26

raw materials for synthesis | fuels for energy

Question 27

how do we harvest energy from fuels

Answer 27

digest large molecules into smaller ones break bonds and move electrons from one molecule to another as electrons move they “carry energy” with them that energy is stored in another bond, released as heat or harvested to make ATP

Question 28

how do we move electrons in biology

Answer 28

electrons cannot move alone in cells | they move as part of an H atom

Question 29

oxidation and reduction in terms of energy

Answer 29

oxidation - exergonic, releases energy | reduction - endergonic, stores energy

Question 30

cellular respiration

Answer 30

The process by which mitochondria break down glucose to make ATP two types: aerobic and anaerobic

Question 31

aerobic respiration

Answer 31

requires oxygen and carried out by plants, animals, and some bacteria

Question 32

anaerobic respiration

Answer 32

requires no oxygen and carried out by yeast, some bacteria, and sometimes animals

Question 33

3 overall goals of cellular respiration

Answer 33

-to break the bonds between glucose to result in carbon dioxide (producing 6 CO2) -to move H atom electrons from glucose to oxygen to form water (producing 6 H2Os) -to trap as much free energy as possible released in the form of ATP (ultimate goal) accomplished through substrate-level phosphorylation and oxidative phosphorylation

Question 34

substrate-level phosphorylation

Answer 34

ATP is formed directly in an enzyme-catalyzed reaction a phosphate-containing compound (PEP or GDP) transfers a phosphate group directly to ADP, forming ATP This type of energy transfer occurs in glycolysis and in the Krebs cycle

Question 35

oxidative phosphorylation

Answer 35

ATP is formed indirectly involves sequential redox reaction, with oxygen being the final electron acceptor More complex Yields more ATP than substrate-level phosphorlation

Question 36

cellular respiration stages and changes

Answer 36

Stage 1: Glycolysis – a 10 step process occurring in the cy p to lasm Stage 2: Pyruvate Oxidation – a one-step process in the mitochondrial matrix Stage 3: The Krebs cycle – an 8 step cyclical process in the mitochondrial matrix Stage 4: Electron transport and chemiosmosis – a multistep process in the mitochondrial cristae

Question 37

The ETC consists of:

Answer 37

4 protein complexes: NADH dehydrogenase complex, complex II, cytochrome bc complex, cytochrome c oxidase complex 2 mobile electron carriers: ubiquinone/coenzyme Q, cytochrome C

Question 38

ATP synthase

Answer 38

protons enter the matrix through proton channels associated with ATP synthase (ATPase) for every H+ that passes through, enough free energy is released to create 1 ATP from the phosphorylation of ADP

Question 39

chemiosmosis

Answer 39

a process that uses energy in a hydrogen ion gradient across the inner mitochondrial membrane to drive phosphorylation of ADP to form ATP

Question 40

regulation of aerobic respiration

Answer 40

feedback inhibition

Question 41

speeding up aerobic respiration

Answer 41

high levels of ADP low levels of citrate both act on phosphofructokinase (PFK)

Question 42

slow down aerobic respiration

Answer 42

``` excess ATP (acts on PFK) accumulation of citrate (acts on PFK) excess NADH (acts on pyruvate dehydrogenase) ```

Question 43

lipid catabolism

Answer 43

2nd energy source triglycerides are digested into fatty acids and glycerol glycerol can be converted to G3P (glyceraldehyde-3-phosphate) and enter glycolysis fatty acids undergo beta oxidation (same process as pyruvate oxidation) and enter Krebs cycle

Question 44

protein catabolism

Answer 44

first go through deamination where amino groups are removed and converted to ammonia waste product amino acids are oxidized and can enter as pyruvate, acetyl units, or molecules in Krebs cycle

Question 45

total yield of ATP from cellular respiration

Answer 45

2 ATP from glycolysis 2 ATP from krebs cycle 4 ATP from NADH formed during glycolysis 6 ATP from NADH formed during pyruvate oxidation 22 ATP from NADH and FADH2 formed during Krebs cycle total of 36