Life at the Molecular Level

Question 1

Describe life processes in terms of the laws of thermodynamics

Answer 1

• energy can be converted from one form to another but not created or destroyed
• all energy transformations ultimately lead to more entropy in the universe
• true for living organisms, although processes create more order, the heat created is released into universe creating more entropy there

Question 2

What is a dynamic steady state?

Answer 2

• In biological reaction pathways, products from one are used in the next pathway and so are unable to reach equilibrium
• food is supplied and waste is removed in a continuous state
• this is called a dynamic steady state

Question 3

A dynamic steady state allows the entropy produced to be

Answer 3

used in the construction of higher order compounds

Question 4

Define metabolism

Answer 4

The chemical processes in a living organisms that allow food to be used for tissue growth
- mix of summative (anabolism) and degradative (catabolism) reactions

Question 5

Give two features of catabolism

Answer 5

• occurs with -ve ∆G

- spontaneous

Question 6

Give two features of anabolism

Answer 6

• occurs with +ve ∆G

- not spontaneous

Question 7

How are anabolism and catabolism interdependent?

Answer 7

Energy obtained from catabolic reactions is used up in anabolic reactions to produce more highly ordered compounds

Question 8

Describe the structures and contributions to metabolic flow of ATP/ADP

Answer 8

ATP/ADP act as free energy carriers, coupling anabolic and catabolic reactions using phosphate group transfers

Question 9

Describe the structures and contributions to metabolic flow of NADP, NAD and FAD

Answer 9

NADP, NAD and FAD are used in redox reactions as electron carriers