B1.3 Flashcards
What is your metabolism?
Chemical reactions in the body’s cells that change food into energy
Metabolic rate is the speed of this occurring
What are carbohydrates?
Some are polymers made from smaller carbohydrate monomers such as sugar
Sucrose, lactose, starch
Carbohydrase enzymes break down carbohydrates
Amylase breaks down starch
What are proteins?
Polymers formed by amino acids
Protease breaks down proteins into mino acids
What are lipids?
Fats and oils that we eat
Used for insulation and buoyancy by some animals
Synthesised from 3 fatty acid molecules and glycerol
Lipase breaks down lipids into them
What is respiration?
Chemical, reaction in which living cells release energy from glucose and oxygen to produce ATP
What is the word equation for aerobic respiration?
Glucose + oxygen > carbon dioxide + water
What is ATP used for?
- synthesise larger molecules from smaller ones
- for movement, contracting muscles
- to stay warm
Where does respiration occur?
Mitochondria of a cell
Different cells contain different numbers of mitochondria depending on how active the cell is
What type of reaction is respiration?
Exothermic (releases energy)
What is anaerobic respiration?
During exercise your muscles need more energy than normal, so heart rate and breathing increase
But during strenuous exercise your heart rate cannot increase fast enough to meet the demand so you respire anaerobically (without oxygen)
Oxygen needed to react with the lactic acid is called the oxygen debt
What is the word equation for anaerobic respiration ?
Glucose > lactic acid
Glucose isn’t fully broken down so a poisonous lactic acid is produced
Why do we aerobically produce?
Produces more ATP as glucose molecule is fully broken down
Lactic acid can cause cramps and fatigue
How do other organisms use anaerobic respiration?
When energy needs to be transferred quickly
Takes place in plants when no oxygen is available (waterlogged soils)
What is fermentation?
Anaerobic respiration in microorganisms and plant cells produces ethanol and carbon dioxide
Word equation for fermentation?
Glucose > ethanol + carbon dioxide
