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Flashcards in 1.6 Cell Metabolism Deck (42)
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1

Definition of cell metabolism

All the enzyme controlled reactionsthat occur in a cell at the same time

2

The two groups that reactions in a cell can be categorised into

•Catabolic
•Anabolic

3

Explain an anabolic pathway

•Requires energy
•Involves biosynthetic processes (large molecules synthesised from small molecules)

4

Explain a catabolic pathway

•Releases energy
•Involves the breakdown of large molecules into smaller molecules

5

An example of a catabolic reaction

Aerobic respiration

6

An example of an anabolic pathway

Protein synthesis

7

Definition of a metabolic pathway

A series of chemical reactions that follow on, one after the other

8

What each stage in a metabolic pathway is controlled by

Enzymes

9

Example of a reversible metabolic pathway

The conversion of pyruvate into lactic acid in animal cells

10

Example of an irreversible metabolic reaction

The conversion of pyruvate into ethanol and CO2 in plant cells

11

What alternative routes do in metabolic reactions

Bypass steps in a pathways

12

The two ways metabolic pathway can be controlled

•the presence or absence of particular enzymes in the pathway
•regulation of the rate of reaction of key enzymes within the pathway

13

The result of the genes for some enzymes being continuously expressed

•the enzymes are always present in the cell
•their control involves the regulation of their rate of reaction

14

The two molecules regulation of rate of reaction is controlled by

•intracellular
•extracellular

15

Describe the work of extracellular signal molecules

Secreted by a particular cell but work elsewhere in the body

16

Example of extracted signal molecules

Hormones which travel in the bloodstream to reach target tissues
eg. Insulin produced in the pancreas works on the liver

17

Describe the work of intracellular signal molecules

Work inside the cell that produces them

18

Where enzymes are found

Every living cell

19

What an enzyme is

Biological catalysts made of protein

20

What would happen if enzymes weren't present in cells

Chemical reactions would occur in cells to slowly for life to exist

21

What activation energy is

The energy needed to start a reaction

22

Basic work of enzymes

Enzymes lower the activation energy needed to start a chemical reaction

23

Symbol for activation energy

Ea

24

Define what is ment by affinity

The active site having a chemical attraction to the substrate

25

Explain the meaning of induced fit

•structural changes occur so that the active site fits precisely around the substrate
•the substrate induces the active site to change shape

26

How enzymes reduce the activation energy required for the reaction to occur

Orientating and then holding the reactants close together

27

Why the end products are released from the enzyme

The end products have a lower affinity for the active site

28

What the direction and speed of an enzyme controlled reaction are controlled by

The concentrations of both the substrate and the end product

29

In what direction does the increase in the substrate concentration drive to the reaction in

In the direction of the end product

30

What drives a sequence of reactions in a particular direction

•presence of a substrate
•removal of a product