B9 Flashcards
Organisms need energy for-
- chemical reactions to build larger molecules
- movement - animals
- keeping warm - animals
- active transport- plants
Aerobic respiration equation
Glucose + oxygen– carbon dioxide + water
How does the body respond to exercise?
- muscle fibres require energy to contract and cause movement. They contain many mitochondria which carry out aerobic respiration and release energy needed
- muscle fibres store glycogen which can be converted back into glucose for use in respiration when needed
- heart rate, breathing rate and breathing volume increase to supply muscles with more oxygenated blood
If insufficient oxygen is supplied, what happens?
- anaerobic respiration takes places in muscles.
- this incomplete oxidation of glucose causes build up of lactic acid and creates oxygen debt
- during long periods of exercise, muscles become fatigued
Anaerobic respiration
Occurs without oxygen, less energy is transferred
Animals - anaerobic respiration equation
Glucose – lactic acid
Plants/yeast cells - anaerobic respiration– equation
Glucose – ethanol + carbon dioxide
Lactic acid that’s built up because of anaerobic respiration must be broken down using what and into what?
Using oxygen
Into carbon dioxide and water
Oxygen required to break down lactic acid is called what?
Oxygen debt
Why does breathing and heart rate remain high after exercise?
To provide extra oxygen required to remove lactic acid
Lactic acid + oxygen –
Carbon dioxide + water
Metabolism
Sum of all reactions that take place in a call/the body
Energy transferred by respiration in cells is used by the organism for
Continual enzyme controlled processes of metabolism that synthesise new moleculesb
What can glucose be converted into?
Starch, glycogen, cellulose
Use of glucose and nitrate ions forms…
Amino acids, which are used to synthesise proteins
Liver carries out many metabolic functions, for example
Removal of lactic acid
Blood flowing through the muscles carries lactic acid to the liver where it’s converted into…
Glucose
Oxygen debt is repaid once glucose is broken down ____ to form ____ and ___
Aerobically
Carbon dioxide
Water
If glucose isn’t required, it’s
Converted into glycogen and stored in the liver
