Food (whole Chp) Flashcards
Why is food important
Provide energy
Growth and repair
Trace elements
Only needed in small amounts
3 examples of trace elements
Copper, iron, zinc
Biomolecules
Chemicals that are made inside a living thing
Elements in carbohydrates
Carbon, Hydrogen, Oxygen
Carbohydrate ratio
2:1
Monosaccharide
Consists of a single sugar unit
Example and function of monosaccharides
Glucose - energy
Fructose - sweeter to taste than glucose
Disaccharide
Two sugar units joined together
Examples of disaccharides
Sucrose, maltose
What does sucrose consist of
Glucose + fructose
What does maltose consist of
Glucose + glucose
Polysaccharides
Consist of many sugar units joined together
Example of polysaccharides
Starch, cellulose, glycogen
Function of starch
Provides energy
cellulose
Found in cell wall of plants
Where is glycogen found
Liver and muscles
Elements in lipids (fats)
C , H, O
Difference between fats and oils
Fats - solid @ room temp
Oils - liquid @ room temp
Sources of lipids
Butter, oil
How do fats differ from carbohydrates
Carbohydrates have a fixed ratio of elements
Lipids have no fixed ratio (v. little oxygen)
Structure of triglyceride
One glycerol molecule + 3 fatty acids
Structure of phospholipid
Glycerol molecule, 2 fatty acids and a phosphate group
Elements/chem. composition in proteins
Carbon, Hydrogen, Oxygen and Nitrogen
Sometimes sulphur and phosphorous
Sources of protein
Meat, fish
What are amino acids
Basic units of protein
How many amino acids in a peptide bond
Less than 20
How many amino acids in a polypeptide
More than 20
How many amino acids in proteins
More than 200
Difference between amino acids and protein
Amino acids- basic unit of protein
Protein- chain of many amino acids
Fibrous protein
No folding
Where is fibrous protein found
Hair and nails (keratin)
Shape of globular protein
Folded
E.g of globular protein
Enzymes
Water soluble vitamin + source
Vitamin C - fresh fruits
Fat soluble vitamin + source
Vitamin D - egg yolk
Structural role of carbohydrates
Cellulose helps form plant cell walls
Structural role of protein
Keratin found in hair
Structural role of lipids
Phospholipids help form structure of cell membrane
Metabolic role of carbohydrates
Provide energy
Metabolic role of lipids
Provide energy
Metabolic role of proteins
Enzymes - control metabolic reactions
Another metabolic role of protein
Antibodies help fight infection
Metabolic role of vitamin C
Helps form connective tissue
Metabolic role of vitamin D
Healthy bones
Use of calcium in plants
Helps bind cell walls together
Use of magnesium in plants
Forms part of the structure of chlorophyll
Use of calcium in animals
Strong bones
Use of iron in animals
Forms part of structure of haemoglobin
3 reasons for water
Good solvent
Helps regulate body temp
Provides basis for transport
How much water in human body
70%
How much water in plants
90%
Anabolic
Convert smaller molecules into larger molecules
Example of an anabolic reaction in plants
Photosynthesis
Example of an anabolic reaction in humans
Protein synthesis
Catabolic reactions
Larger molecule broken down into smaller molecules (release energy)
Example of catabolic reaction
Respiration
Where does respiration take place
In a cell
