Metabolism

Question 1

what are the functions of metabolism

Answer 1

Cells need a source of energy

This energy is provided by electrons with negative redox potential. (high energy electrons)

Cells need anabolic reductive power for anabolic processes (provided by high energy electrons)

Cells need a source of carbon to build cellular components

Question 2

how do plants synthesise macromolecules

Answer 2

using sunlight as energy

Question 3

Metabolism =?

Answer 3

Catabolism + Anabolism

Question 4

Catabolism

Answer 4

Large complex organic molecules are decomposed into small molecules
It is degradative
It is oxidative
Energy is liberated
It is converging

Question 5

Anabolism

Answer 5

Large complex organic molecules are constructed from small molecules
It is biosynthetic
It is reductive
Energy is required
It is diverging

Question 6

what is referred to as a redox reaction

Answer 6

Oxidation-reduction reaction, this is where electrons are transferred from one molecule to another

Question 7

Oxidation states of carbon

Answer 7

(Most reduced state with the highest free energy) alkane> alcohol> aldehyde>carboxylic acid> carbon dioxide> (final product or catabolism)

Question 8

glucose oxidation in steps

Answer 8

Reduces the activation energy so that reaction can happen at 37’C
Reduces the free energy released
Can be coupled to endergonic reactions in cells
Does not damage the cell
Provides convenient control points
Can be integrated with other cellular communication

Question 9

Electron flow in chemotrophs

Answer 9

Organic compounds (carbohydrates, amino acids, lipids) are oxidised to release high energy electrons

Organic cofactors act as electron carriers
NAD+ + 2 H+ is reduced to NADH + H+
FAD + 2H+ is reduced to FADH2

A terminal electron acceptor is reduced
aerobically: O2 —> H2O

Question 10

Energy-centred view of metabolism

Answer 10

Nutrients such as glucose+O2 are catabolized, oxidative exergonic, and turn to CO2 +H2O

ADP+Pi are catabolized to atp,
ATP is anabolised to ADP+Pi

Question 11

Enzymes

Answer 11

They are proteins that catalyse the conversion of a substrate into a product
They often require co-enzymes, ATP

They perform most chemical reactions in cells

Question 12

What is the simple rule in naming enzymes

Answer 12

The enzyme name is derived from its substrate and its action:

Substrate action- ase

Question 13

What is a function and an example of a oxidoreductases?

Answer 13

Function: All the enzymes catalyzing oxide-reductions
Example: Alcohol dehydrogenase

Question 14

what are a function and an example of a transferase?

Answer 14

Function: Transfer a group onto a substrate
Example: UMP kinase

Question 15

what are a function and an example of a hydrolase

Answer 15

Function: Catalyse the hydrolysis of various bond
Example: aminoacyl- tRNA hydrolase

Question 16

what are a function and an example of a Lysases

Answer 16

Function: Cleave C-C, C-O, C-N, and other bonds by other means by then by hydrolysis or oxidation
Example: pyruvate decarboxylase

Question 17

what are a function and an example of an isomerase

Answer 17

Function: Catalyse changes within one molecule
Example: DNA topoisomerase

Question 18

what are a function and an example of a Ligase

Answer 18

Function: Catalyse the joining of two molecules with concomitant hydrolysis of diphosphate bond in ATP or a similar triphosphate
Example: DNA ligase (ATP)

Question 19

what is the name and give an example of an enzyme that transfers phosphate groups

Answer 19

Name: Kinase
Example: Phosphofructokinase

Question 20

what is the name and give an example of an enzyme that rearranges molecules

Answer 20

Name: Isomerase
Example: Isomerase

Question 21

what is the name and give an example of an enzyme that makes a molecule from parts

Answer 21

Name: Synthase
Example: ATP synthase

Question 22

what is the name and give an example of an enzyme that removes hydrogen

Answer 22

Name: Dehydrogenase
Example: Isocitrate dehydrogenase

Question 23

what is the name and give an example of an enzyme that removes phosphate from proteins

Answer 23

Name: Phosphate
Example: Dual specificity phosphate.

Question 24

What is a function and example of transferases

Answer 24

Function: Transfer a group onto a substrate
Example: UMP kinase

Question 25

how does glucose transport into cells

Answer 25

via passive facilitated diffusion through glucose transporters

Question 26

GLUT1

Answer 26

Tissue: Brain
Characteristics: Low Km

Question 27

GLUT2

Answer 27

Tissue: Liver, pancreatic beta cells
Characteristics: High Km, insulin dependent

Question 28

GLUT3

Answer 28

Tissue: Brain
Characteristics: Low Km

Question 29

GLUT4

Answer 29

Tissue Muscle, adipose tissue
Characteristics: Insulin dependent

Question 30

GLUT

Answer 30

Tissue: Gut
Characteristics: Fructose dependent