Chaoter 8- Intro To Metabolism

Question 1

Cellular respiration

Answer 1

Drives the cell by extracting the energy stored in sugars and other fuels

Question 2

Metabolism

Answer 2

Totality of an organisms chemical reaction

A cells metabolism is thousands of chemical rxn that happen in a cell organized as metabolic pathways

Question 3

Metabolic pathways

Answer 3

Begins w/ a specific molecule, that is then altered in a series of defined steps, resulting in a certain product
Structures in the cell help bring order to metabolic pathways

Question 4

Catabolic pathways

Answer 4

Some metabolic pathways release energy by breaking down complex molecules into simpler compounds
Major pathway of catabolism is cellular respiration
Atoms are rearranged and energy is released resulting in lower energy break down products

Question 5

Anabolic pathways

Answer 5

Consume energy to build complicated molecules from simpler ones
Ex) synthesis of a protein

Question 6

Bioenergentics

Answer 6

Study of how organisms manage their energy resources

Question 7

Energy

Answer 7

Capacity to cause change

Question 8

Kinetic energy

Answer 8

Energy of motion

Heat/thermal energy is kinetic energy associated w/ random movement of atoms or molecules

Question 9

Potential energy

Answer 9

Storage energy or energy that matter posses bc if it’s location or structure

Question 10

Chemical energy

Answer 10

Potential energy available

Question 11

Thermodynamics

Answer 11

Study of energy transformations that occur in a collection of matter 2 laws of thermodynamics govern energy transformations in organisms and all other collections of matter

Question 12

First law of thermodynamics

Answer 12

The energy of the universe is constant
The cheetah converts the chemical energy of the organic molecules in its food to kinetic and other forms of energy as it carries biological processes
During energy transfer some energy becomes unusable (most energy is lost as heat)

Question 13

Entropy

Answer 13

Measure of disorder or randomness more random more entropy

Question 14

Second law of thermodynamics

Answer 14

Every energy transfer or transformation increases the entropy of the universe
Increased entropy is shown in the physical disintegration of a system’s organized structure but in the universe it’s shown as increasing heat
For a process to occur on its own it must increase the entropy of the universe

Question 15

Biological order and disorder

Answer 15

Cells create ordered structures from less organized starting materials
Ex) amino acids are ordered into specific sequences of polypeptide chains
Organisms can also take in organized forms of matter and energy and replaces them w/ less ordered forms
Ex) animals obtain starch protein and other complex molecules

Question 16

Free energy

Answer 16

Measures the portion of a systems energy that can perform work when temperature and pressure are uniform throughout the system as in a living cell
Processes with a - 🔼G are spontaneous

Question 17

Equilibrium

Answer 17

Maximum stability
Systems will never move away from equilibrium spontaneously bc it will have a +🔼G
Systems at equilibrium are a minimum G and can do no work
Cells are not in equilibrium

Question 18

Exergonic rxn

Answer 18

These reactions are spontaneous greater decrease in free energy the greater the amount of work can be done
-🔼G
Energy outward
Uphill rxn
Releases energy

Question 19

Endergonic rxn

Answer 19

Absorbs free energy from its surrondings stores free energy in molecules
🔼G is positive
Not spontaneous

Question 20

Mechanical work

Answer 20

Contacting of muscle cells and movement of chromosomes during cellular respiration

Question 21

Transport work

Answer 21

Pumping of substance across membranes against the direction of spontaneous movement

Question 22

Chemical work

Answer 22

The putting of exergonic rxn which would not occur spontaneously such as a synthesis of polymers from monomers

Question 23

Energy coupling

Answer 23

Use of an exergonic process to drive and endergonic one this is a way cells manage their energy resources

Question 24

Structure and hydrolysis of ATP

Answer 24

ATP contains sugar ribose w/ the nitrogenous base adenine and a chain of 3 phosphate groups bonded to it these bonds can be broken by hydrolysis when a terminal bond is broken a molecule of inorganic phosphate leaves the ato which becomes adenosine diphosphate (ADP)
ATP is useful in the cell bc the energy is releases on hydrolyzing a phosphate group is somewhat greater than the energy other molecules can deliver since all 3 phosphate groups are negative it makes them unstable which is why it releases a lot of energy

Question 25

ATP cycle

Answer 25

The shuttling of inorganic phosphate and energy, it coupled the cells energy yeilding (exergonic) processes to the energy consuming (endergonic) ones the atp cycle moves at an astonishing pace

Question 26

Activation energy/ free energy of activation energy

Answer 26

The initial investment of energy for starting a rxn the energy required to contort the reactant molecules so the bonds can change
Activation energy is often supplie don’t he form of heat that the reactant molecules absorb from the surroundings
Heat increases the speed of the reaction molecules so they collide more often and more forcefully

Question 27

How enzymes lower the E a barrier

Answer 27

The barrier for selected rxn must occasionally be surmounted for cells to carry out processes necessary for life
An enzyme catalyzes a rxn by lowering the E a barrier enabling the reactant molecules to aboard enough energy to reach the transition state even at moderate temperatures

Question 28

Substrate

Answer 28

The redacting an enzyme acts on

Question 29

Enzyme substrate complex

Answer 29

The enzyme forms this when an enzyme binds to its substrate

Question 30

Active site

Answer 30

The restricted region of the enzyme molecule that binds to the substrate
Substrate is held here by weak interactions (hydrogen and ionic bonds)

Question 31

Induced fit

Answer 31

The substrate causes the enzyme to change so that the active site fits even more snugly around the substrate

Question 32

Optimal condition

Answer 32

Favor the most active confirmation for the enzyme molecule

Question 33

Cofactors

Answer 33

Nonprotien helpers for catalytic activity (required by many enzymes)
If it’s an organic molecule it’s called a coenzyme

Question 34

Competitive inhibitors

Answer 34

Reversible inhibitors that resemble the normal substrate molecules and compete fr admission into the active site they reduce the productivity of enzymes by blocking substrates from entering the active site

Question 35

Non competitive inhibitors

Answer 35

Don’t directly compete w/ substrate to bind to the enzyme at the active site instead they impede enzymatic rxn by binding to another part of the enzyme

Question 36

Allosteric regulation

Answer 36

Term used to describe any case in which a proteins function at one site is affected by the binding of a regulatory molecule to a separate site

Question 37

Activator

Answer 37

The binding of an activator to a regulatory site stabilizes the confirmation that has functional active sites

Question 38

Inhibitor

Answer 38

The binding of an inhibitor stabilizes the inactive form of the enzyme

Question 39

Cooperatively

Answer 39

Amplifies the response of enzymes to substrates

Question 40

Feedback inhibition

Answer 40

A metabolic pathway is switched off by inhibitory binding of its end product to an enzyme that acts early in the pathway
ATP allosterically inhibits an enzyme in atp generating pathway the result is feedback inhibitor (a common method of metabolic control)
Prevents the cell from wasting chemical resources by synthesizing more isoleucine than necessary