Part 3: Cellular Energetics

Question 0

Enzymes

Answer 0

Biological catalysts; enable cells to break chemical bonds without using (much) energy; speed up reaction without changing it by lowering the reaction’s activation energy

Question 1

Bioenergetics

Answer 1

The study of how cells carry out the processes necessary for life, and the way in which cells release energy when they need it and store it when they don’t; how energy from the sun is transformed into energy in living things

Question 2

Exergonic reactions

Answer 2

Products have less energy than reactions, energy is given off during reaction

Question 3

Endergonic reactions

Answer 3

Reactions that require an input of energy; products have more energy than reactants

Question 4

Activation energy

Answer 4

Energy required to start a reaction and break the chemical bonds of the reactants; energy barrier

Question 5

Enzyme specificity

Answer 5

Property of enzymes that they can only catalyze one type of reaction; each enzyme can only bind to one specific substrate

Question 6

Substrate

Answer 6

Targeted molecules in an enzymatic reaction

Question 7

Active site

Answer 7

Place on the enzyme that a substrate binds to

Question 8

Enzyme-substrate complex

Answer 8

Molecule formed by the binding of a substrate onto an enzyme

Question 9

Induced fit

Answer 9

Enzyme slightly changes shape to accommodate substrate

Question 10

Coenzymes

Answer 10

Organic factors that aid an enzyme in catalyzing a reaction; accept electrons and pass them on to another substrate; ex. Vitamins

Question 11

Cofactors

Answer 11

Inorganic molecules that help catalyze reactions; usually metal ions (Fe+2)

Question 12

Allosteric sites

Answer 12

Sites other than the active site that other substances can bind to

Question 13

Allosteric regulators

Answer 13

The “other substances” that can bind to the allosteric site to inhibit or activate enzymes

Question 14

Allosteric inhibitor

Answer 14

Allosteric regulator that inactivates the enzyme

Question 15

Allosteric activator

Answer 15

Allosteric regulator that induces an enzymes function

Question 16

Feedback inhibition

Answer 16

Formation of an end product inhibits an earlier reaction in the sequence

Question 17

Competitive inhibition

Answer 17

A substance that has the shape that fits the active site of an enzyme blocks the substrate from binding to the active site and inactivates enzyme

Question 18

Noncompetitive inhibition

Answer 18

Inhibitor binds with enzyme at a place other than the active site and inactivates enzyme by changing its shape

Question 19

First law of thermodynamics

Answer 19

Energy cannot be created or destroyed

Question 20

Second law of thermodynamics

Answer 20

Energy transfer leads to less organization; universe tends toward chaos (entropy)

Question 21

Entropy

Answer 21

Chaos, disorder

Question 22

Photosynthesis

Answer 22

Transformation of solar energy into chemical energy

6CO2 + 6H2O + sunlight –> C6H12O6 + 6O2

Question 23

Cellular respiration

Answer 23

C6H12O6 + 6O2 –> 6CO2 + 6H2O + ATP
Way to synthesize ATP
Aerobic or anaerobic

Question 24

Aerobic respiration

Answer 24

Cell resp. in the presence of O2

Question 25

Anaerobic respiration

Answer 25

Cell resp. not in the presence O2

Question 26

Glycolysis

Answer 26

Splitting of glucose; stage one of cell resp.; occurs in cytoplasm, net 2 ATP, products: 2 pyruvate (3C molecules) and 2 NADH

Question 27

Pyruvic acid (pyruvate)

Answer 27

3-Carbon molecules, formed from glucose in glycolysis

4 fates: acetyl CoA (aerobic), lactic acid (anaerobic), glucose (glyconeogenesis), or

Question 28

Parts of the mitochondria

Answer 28

Matrix- innermost area
Inner mit. Memb.
Intermemb. Space
Outer mit. Memb.

Question 29

Acetyl CoA

Answer 29

2C molecule formed from pyruvate during transition reaction

Question 30

Krebs cycle (citric acid cycle)

Answer 30

acetyl CoA combines with oxaloacetate (4C) to form citric acid (6C) and continues thru cycle
Products: 1 ATP, 3 NADH, 1FADH2, 2CO2 per pyruvate (x2 to get per glucose)

Question 31

Cytochromes

Answer 31

Iron-containing carrier molecules in the electron transport chain

Question 32

pH gradient (proton gradient)

Answer 32

Created by pumping H ions into the intermemb. space, energy from gradient responsible for the production of ATP

Question 33

ATP synthase

Answer 33

Channels on the inner mit. memb. that H+ ions pass through to generate ATP

Question 34

Oxidative phosphorylation

Answer 34

The process by which ATP is synthesized as a result of the flow of protons through the ATP synthase in the mitochondria
34 ATP (NADH makes 3, FADH makes 2)

Question 35

Fermentation

Answer 35

Anaerobic resp.- pyruvate converted to either lactic acid (animals) or ethanol (plants)