Food Flashcards
3 reasons why food is necessary
Source of energy
Make chemicals for metabolic reactions
Raw materials for growth and repair of structures
How many elements found in food
14
Name the common elements
Carbon Hydrogen Oxygen Nitrogen Phosphorous Sulfur
Elements present in dissolved salts
Sodium Magnesium Chlorine Potassium Calcium
Trace elements
Iron
Copper
Zinc
Four types of bio molecules
Carbs
Lipids
Proteins
Vitamins
Elements in carbs and ratio
Carbon Hydrogen Oxygen Twice as much H as C and O Cx(H2O)y
Are monosaccharides soluble in water
Yes
Are monosaccharides sweet
Yes
Are disaccharides soluble in water
Yes
Are disaccharides sweet
Yes
Name two monosaccharides
Glucose
Fructose
Name two disaccharides
Maltose
Sucrose
Are polysaccharides sweet
No
Are polysaccharides soluble in water
Not usually/ not fully
Name three polysaccharides
Starch
Cellulose
Glycogen
Structural role of a carb
Cellulose forms plant cell walls
Metabolic role of a carb
Glucose broken down in photosynthesis to release energy
Is starch easily digested
Why
Yes
Molecules arranged in a chain
Can cellulose be easily digested
No
Cross-bonding between molecules
Used as roughage in our diet
Where do animals store glycogen
In their liver and muscles
Elements in lipids and ratio
Carbon
Hydrogen
Oxygen
No simple ratio. V little oxygen
Structure of a triglyceride
One glycerol + three fatty acids
Structure of a phospholipid
One glycerol + two fatty acids + one phosphate
Function of phospholipids
Important in structure of cell membranes
Metabolic role of lipids
Respiration
Structural roles (2) of lipids
Cell membranes
Heat insulation
Elements in proteins
Carbon
Hydrogen
Oxygen
Nitrogen
What are proteins made of
Amino acids
How many amino acids are in a peptide bond
Less than 20
What is the next bond after a peptide bond
Polypeptide bond
How many amino acids are in a protein
More than 200
How are different proteins made
By combining the 20 types of amino acids in different ways
Name a fibrous protein and where it’s found
Keratin
Hair and nails
Characteristics of a fibrous protein
Little or no folding
Long fibres
Strong and tough
Characteristics of globular proteins
Lots of folding
Rounded shapes
Example of a globular protein
Egg white
Enzymes
Amino acids are not stored in the body. What happens to them?
Surplus: taken to liver-> urea -> kidneys -> excreted
Structural role of proteins
Keratin, hair
Myosin, muscles
Metabolic roles (2) of proteins
Used as enzymes to control reactions
From antibodies
Can the body make vitamins?
No
Name a water soluble vitamin
C
Name a fat soluble vitamin
D
Metabolic roles (2) of Vitamin C
Helps immune system
Formation of connective tissue
Disease caused by Vitamin C deficiency
Scurvy
Metabolic role of vitamin D
Healthy bone and teeth formation
Disease caused by Vitamin D deficiency
Rickets
Two minerals needed by plants
Magnesium
Calcium
Two minerals needed by animals
Iron
Calcium
Use for magnesium in plants
Form chlorophyll
Use for calcium in plants
Cell walls attach to eachother
Use for calcium in animals
Form bones and teeth
Use of iron in animals
Form haemoglobin
What percentage of human body molecules is water
99%
What % of human body mass is water
60%
What % of most plants is water
90%
Why is water essential to life. Three reasons
All metabolic reactions occur in it
Basis for transport systems
Environment where organisms can live
Name two types of energy transfer reactions
Anabolic and catabolic
Metabolism
All reactions taking place in an organism
What do anabolic reactions do
Use energy to convert smaller molecules to bigger
What do catabolic reactions do
Release energy when a complex molecule is broken down
Two examples of catabolic reactions
Respiration
Digestion
Two examples of anabolic reactions
Formation of muscle from amino acids
Photosynthesis
