Metabolism, Energy and ATP

Question 1

What is metabolism?

Answer 1

All the chemical reactions that take place within a living organism

Question 2

What is metabolism usually controlled by?

Answer 2

Enzymes

Question 3

What is a metabolic pathway?

Answer 3

A sequence of enzyme controlled reactions

Question 4

What does the product of one reaction act as in a metabolic pathway?

Answer 4

The substrate for the next

Question 5

What is the last substance produced known as?

Answer 5

End-Product inhibition/feedback regulation which may be used by another part of the cell

Question 6

What are the 2 types of metabolic pathways?

Answer 6

Anabolism
Catabolism

Question 7

What is anabolism?

Answer 7

Build up of larger, more complex molecules from smaller, simple ones

Question 8

What do anabolic reactions require?

Answer 8

Energy

Question 9

What is catabolism?

Answer 9

Breakdown of complex molecules into simple ones

Question 10

What do catabolic reaction release?

Answer 10

Energy

Question 11

2 examples of anabolic, condensation reactions

Answer 11

-Amino Acids into peptides
-Nucleotides into RNA

Question 12

2 examples of catabolic, hydrolysis reactions

Answer 12

-Starch into glucose
-Triglycerides into fatty acids and glycerol

Question 13

How can enzymes be grouped together?

Answer 13

Depending on types of reactions they catalyse

Question 14

Hydrolase Enzymes

Answer 14

Control hydrolysis reactions

Question 15

Oxidoreductase Enzymes

Answer 15

Control redox reactions

Question 16

Transferase Enzymes

Answer 16

Move whole chemical groups e.g Amino Acids

Question 17

Isomerase Enzymes

Answer 17

Change the shape of a molecules (creating an isomer)

Question 18

What is energy?

Answer 18

Ability to do work

Question 19

What are the 2 states of energy?

Answer 19

-Kinetic
-Potential

Question 20

Kinetic Energy

Answer 20

-Energy of motion
-Moving objects perform work by making other objects move

Question 21

Potential Energy

Answer 21

-Stores energy
-An object that is not moving may still have the potential to do work as it has “potential energy”

Question 22

Energy Simple Facts

Answer 22

-Can be changed from one store to another
-Cannot be created or destroyed
-Is released and not produced
-Measured in Joules

Question 23

What is energy needed for?

Answer 23

-Metabolism (anabolism esp)
-Movement within organism and of the organism
-Active Transport
-Maintenance, repair and cell division
-Homeostasis (body temperature esp)
-Secretion of chemicals e.g. hormones

Question 24

Where does energy come from?

Answer 24

See Notes for Diagram

Question 25

What is the main energy currency of living cells?

Answer 25

Adenosine Triphosphate (ATP)

Question 26

What is ATP?

Answer 26

A small water soluble molecule which is therefore easily transported around the cell

Question 27

How does ATP store energy?

Answer 27

As chemical potential energy

Question 28

What is the structure of ATP?

Answer 28

Adenine (Nitrogenous Base)
Ribose Sugar
3 Phosphates

Question 29

How does ATP store energy?

Answer 29

-Each phosphate groups are negativity charged so straining to get away from each other
-Covalent bonds holding P groups together are easily broken
-When covalent bonds break, phosphate is released along with 30.6 kJ mol-1 of energy for each for the first 2 phosphates

Question 30

What is unique about the conversion of ATP to ADP?

Answer 30

Is reversible

Question 31

How is the ATP to ADP conversion reversible?

Answer 31

Energy from respiration can be used to combine ADP with a phosphate to re-form ATP

Question 32

What is the ATP to ADP conversion known as?

Answer 32

Phosphorylation

Question 33

What type of reaction is Phosphorylation?

Answer 33

Condensation reactions

Question 34

What is Phosphorylation catalysed by?

Answer 34

ATP synthase or ATPase

Question 35

How is energy put in and out of Phosphorylation?

Answer 35

Out-by condensation (Phosphorylation)
In-by hydrolysis

Question 36

Why is ATP a bad long term energy storage molecule?

Answer 36

Due to the instability of ATP’s phosphate bonds

Question 37

What type of energy source is ATP?

Answer 37

Immediate

Question 38

ATP as an immediate energy source

Answer 38

-Cell doesn’t need large quantities of ATP
-Maintains only a few seconds supply
-ATP is rapidly reformed so a little goes a long way