Ch. 6

Question 1

What is metabolism?

Answer 1

the overall chemical reactions occuring within an organism at a given time

consists of catabolic and anabolic pathways

Question 2

What is a metabolic pathway?

Answer 2

a series of chemical reactions that either build or destroy complex molecules

2 types: catabolic and anabolic

Question 3

What is an anabolic pathway?

Answer 3

consumes energy to synthesize a complex molecule from simpler molecules

Question 4

What is a catabolic pathway?

Answer 4

releases energy by breaking down complex molecules to simpler molecules

Question 5

What are bioenergetics?

Answer 5

the study of how energy flows through organisms

Question 6

What is energy?

Answer 6

the ability to cause change, especially the ability to do work

Question 7

What is kinetic energy?

Answer 7

energy in motion

Question 8

What is potential energy?

Answer 8

stored energy

Question 9

What is chemical energy?

Answer 9

a form of potential energy where it is available in molecules for release in a chemical reaction

Question 10

What is the First Law of Thermodynamics?

Answer 10

“energy can be transferred and transformed, but cannot be created nor destroyed”

principle of conservation of energy

Question 11

What is the Second Law of Thermodynamics?

Answer 11

“every energy transfer or transformation increases the entropy of the universe

usable forms of energy partly converted to heat

Question 12

What are thermodynamics?

Answer 12

the study of the energy transformations that occur in a collection of matter

Question 13

What is entropy?

Answer 13

a measure of molecular disorder or randomness

Question 14

What is delta G?

Answer 14

the symbol for the change of free energy

delta G = G final state - G initial state

Question 15

What is free energy?

Answer 15

the energy that is available to do work

Question 16

What is an exergonic reaction?

Answer 16

a spontaneous chemical reaction that leads to a net release of free energy

energy-releasing process

Question 17

What is an endergonic reaction?

Answer 17

a non-spontaneous chemical reaction; free energy is absorbed from its surroundings

energy-consuming process

Question 18

Is cellular respiration exergonic or endergonic?

Answer 18

exergonic

Question 19

Is photosynthesis exergonic or endergonic?

Answer 19

endergonic

Question 20

What is adenosine triphosphate? (ATP)

Answer 20

a molecule that releases free energy when its phosphate bonds are hydrolyzed

Question 21

What are the 3 kinds of cellular work?

Answer 21

1. chemical work
2. transport work
3. mechanical work

Question 22

What is chemical work?

Answer 22

pushing of endergonic reactions that would NOT occur spontaneously

Question 23

What is transport work?

Answer 23

pumping of substances across a membrane against the direction of spontaneous movement

Question 24

What is mechanical work?

Answer 24

cell motility and movement of structures within cells

Question 25

What is the ATP cycle?

Answer 25

the process by which cells regenerate ATP * ADP forms when a phosphate group is removed from ATP * ATP forms again when ADP forms a phosphate group

Question 26

What are catalysts?

Answer 26

chemical agents that speed up chemical reactions

Question 27

What are enzymes?

Answer 27

a type of macromolecule (usually proteins) that serve as biological catalysts within living systems

Question 28

What is activation energy?

Answer 28

the amount of energy that is needed for a chemical reaction to start | catalysts lower the EA for reactions --> speeds up reaction rate

Question 29

What is a substrate?

Answer 29

the reactant on which an enzyme works

Question 30

What is an active site?

Answer 30

a region on an enzyme that binds to a protein or other substance during a reaction

Question 31

What is an allosteric site?

Answer 31

a site that allows molecules to either activate or inhibit (or turn off) enzyme activity

Question 32

What is a competitive inhibitor?

Answer 32

substances that reduce the activity of an enzyme by entering the active site in place of the substrate, who structure it imitates

Question 33

What is a noncompetitive inhibitor?

Answer 33

substances that reduce the activity of an enzyme by binding to an allosteric site separate from the active site | binds its target enzyme regardless of the presence of a bound substrate

Question 34

What is feedback inhibition?

Answer 34

* where an enzyme's activity is inhibited by the enzyme's end product * allows cells to regulate how much of an enzyme's end product is produced