Unit 2: Metabolism and Enzymes

Question 1

The sum of all the chemical reactions occurring in an organism.

Answer 1

metabolism

Question 2

This refers to the breaking down of a molecule.

Answer 2

catabolism

Question 3

This process releases “potential” E found in the chemical bond between monomers.
This is an exergonic reaction because it releases heat to the environment
Think Catastrophe; breaking up things.

Answer 3

Catabolism

Question 4

type of reaction that releases heat into the environment

Answer 4

exergonic

Question 5

This is the assembly of molecules.

Answer 5

anabolism

Question 6

This process requires “Kinetic” E to position molecules in away so as to create a chemical bond between monomers.
This is an endergonic reaction because it absorbs energy from the environment.
Think Anabolic steroids; these build muscle.

Answer 6

anabolism

Question 7

type of reaction that absorbs energy from the environment.

Answer 7

endergonic

Question 8

For living organisms, the chemical E of life is found in ___________ _______.

Answer 8

chemical bonds

Question 9

The processes of Cellular Respiration and Digestion ________ the E for use by cells.

Answer 9

release

Question 10

Source of all E for Earth?

Answer 10

sun

Question 11

Why is the sun the source of energy for Earth?

Answer 11

The process of photosynthesis allows plants to store this solar energy in the form of chemical energy (sugar).

Question 12

The study of Heat E and its properties

Answer 12

Thermodynamics ((The study of Heat E (Thermo) and its properties (dynamics.))

Question 13

What is the First Law of Thermodynamics (Also called the Principle of the Conservation of E)?

Answer 13

E cannot be created nor destroyed only transformed or transferred.

Question 14

What is the Second Law of Thermodynamics?

Answer 14

Every E transfer increases the entropy of the universe.

Sunlight(high quality E) going in and heat (low quality E)coming out; it can’t do work.

Question 15

means disorder; unable to do work because it is in a low state of order.

Answer 15

entropy

Question 16

It is referred to as “free” because E is available to perform work. (Mainly making ATP or GTP in a cell.)
Not all E is available. (Some is lost as waste…like when we defecate…same goes for cells too.)
Most E is lost as Heat as a byproduct of the bonds being broken.

Answer 16

Gibbs Free E (represented as “G”)

Question 17

3 types of work performed by living cells

Answer 17

mechanical, transport, metabolic

Question 18

the type of work performed by living cell that is work outside of the cell

Answer 18

mechanical

Question 19

What are the two types of metabolic processes?

Answer 19

Catabolism and Anabolism

Question 20

Made from Ribose sugar (RNA sugar) and the nitrogen base Adenine.
Has 3 negative phosphates linked together which makes it highly unstable like a “compressed spring”. Unstable, means it has the capacity do perform work remember.
ATP converting to ADP gives off energy; ADP being converted to ATP requires energy.(The energy needed to make this bond comes from the “free” e in our food as it is broken down.)(ADP is recycled back to ATP.)

Answer 20

ATP (Adenine Tri-phosphate)

Question 21

The attaching of an unstable phosphorus ion to another molecule to make it unstable and thereby able to perform work. (Take the phosphorus off and it quits working.)

Answer 21

phosphorylation

Question 22

These molecules are Biological Catalysts.

Proteins that speed up and control the rate of a chemical reaction.

Answer 22

enzymes

Question 23

Are enzymes recycled or consumed by reactions?

Answer 23

recycled

Question 24

______ are selective in what they will work with. We used to say they had a “lock and key fit” (old term); we now say it “fits like a glove or has an induced fit”. (new term)
This is like putting on a latex glove… it stretches to conform to the shape of your hand.

Answer 24

Enzymes

Question 25

names usually end with “ase”.

Answer 25

enzymes

Question 26

This refers to the Free E used to start a chemical reaction in motion. (Essentially is the energy for getting the molecules moving and positioned so that it is possible to combine or be torn apart.)

Answer 26

Free E of Activation

Question 27

The energy of _______ is lowered by the action of enzymes. (Enzymes reduce by grabbing the molecule and positioning it correctly… we don’t have to wait for nature to do it.)
Enzymes also replace the need for heat in most chemical reactions (remember heat can make molecules move faster) so that organisms don’t burn up during metabolism.

Answer 27

activation

Question 28

This refers to the molecule that is being affected by the enzyme. (What the enzyme is grabbing and working on.)

Answer 28

substrate

Question 29

This refers to the location where the chemical reaction(s) is taking place between the enzyme and substrate.

Answer 29

active site

Question 30

The relationship between an enzyme and substrate is an Induced Fit , which creates the _______-_________ _________. (Complex meaning “more than one piece in the unit”.)

Answer 30

Enzyme-Substrate Complex

Question 31

The two parts of an Enzyme-Substrate Complex are mainly held together by weak ________ bonds

Answer 31

hydrogen

Question 32

Environmental factors that can affect enzymes ability to work optimally. (3)

Answer 32

Temperature – freeze/cold (cold things don’t move quickly) or Heat causing it to Denature (“unfold”).
pH of the environment
Salt concentrations

Question 33

The Optimal Conditions for most human enzymes

Answer 33

98.6˚F (35 - 40⁰C)
pH usually between 7.2 and 7.6 (The human body’s pH of blood is an average of 7.4.)
Remember, this is an unstable (dynamic) environment. There is an upper limit and a lower limit for enzymes. Beyond the limits, bad things begin to happen. So it is basically, trying to stay between the limits. The limits of “life”.

Question 34

The name implies that these molecules negatively affect an enzymes ability to work optimally. These slow down or stop the rate of the chemical reaction.

Answer 34

inhibitors

Question 35

two types of inhibitors

Answer 35

competitive, non-competive

Question 36

These molecules compete for the active site. (This is because of similar shape.)
These molecules slow down the reaction rate. (These molecules will be removed.)

Answer 36

competitive (inhibitors)

Question 37

These molecules attach somewhere other than the active site causing the shape of the active site to change so the substrate can’t fit into it.
a. These molecules cause the reaction to stop completely

Answer 37

non-competitive (inhibitors)

Question 38

A product in excess shuts down the reaction that is taking place at an earlier point in the pathway.
Prevents “waste” of precious materials and energy by not making more of what is not needed at that time.

Answer 38

Feedback inhibition