Food Flashcards
Ch 3
Definition of nutrition?
the way in which an organism obtains and uses food
Name 3 functions of food.
- growth and repair of cells
- a source of energy
- manufacturing of chemicals for metabolism/metabolic reactions
Name 6 common elements found in food.
carbon
hydrogen
oxygen
nitrogen
sulphur
phosphorus
Name 5 elements that are dissolved in salts.
sodium
magnesium
chlorine
potassium
calcium
Name the 3 trace elements and how much of these are required?
only tiny amounts required…
Iron Copper Zinc
Definition of biomolecules?
chemicals that are made inside a living thing
Name the 4 major types of biomolecules found in food.
carbohydrates,
lipids (fats and oils),
proteins,
vitamins
Name sources of carbohydrates.
bread, pasta, potatoes
Carbohydrates are composed of what three elements?
carbon, hydrogen and oxygen
Carbon, hydrogen and oxygen in carbohydrates are present in what ratio?
1:2:1 ratio
Whats the general formula of carbohydrates?
Cx(H2O)y
Whats the formula for glucose?
C6 H12 O6
What are the 3 types of carbohydrates?
monosaccharides,
disaccharides,
polysaccharides
What are monosaccharides?
single/one sugar unit
Give 2 examples of monosaccharides.
glucose, fructose
Describe monosaccharides.
simplest and smallest type of carbohydrate.
sweet to taste.
soluble in water.
What are disaccharides?
two sugar units
Give 2 examples of disaccharides.
maltose, sucrose
Describe disaccharides.
sweet to taste.
soluble in water.
What are polysaccharides?
many sugar units
Give 3 examples of polysaccharides.
cellulose, glycogen, starch
Describe polysaccharides.
insoluble/slightly soluble in water.
not sweet-tasting.
What are some metabolic roles/functions of carbohydrates?
- glucose made in photosynthesis
- glucose is broken down to release energy
- source of energy
What are some structural roles of carbohydrates? (2 are polysaccharide related)
- cellulose makes up cell wall in plant cells
- animals store glucose as glycogen in muscles and liver
- plants store glucose as starch in leaves and roots
What are some sources of lipids?
butter, oils, margarine
Lipids are composed of what three elements?
carbon, hydrogen, oxygen
Do lipids have a ratio?
they do not have a ratio
Whats the difference beetween fats and oils?
fats are solid at room temperature.
oils are liquid at room temperature.
The basic unit of lipids is?
triglyceride
How are triglycerides formed?
one glycerol joined to 3 fatty acids
Where are triglycerides found?
in fatty foods
How are phospholipids formed?
one glycerol joined to 2 fatty acids and a phosphate
Where are phospholipids found?
in cell membranes
What are 2 differences between triglycerides and phospholipids?
- phospholipids have a phosphate group, triglycerides do not.
- phospholipids have 2 fatty acids, triglycerides have 3 fatty acids.
What is a metabolic role of lipids?
Energy (storage/source)
What is a structural role of lipids?
formation of cell membrane
Sources of protein?
(red) meat, fish, eggs, nuts
Proteins are always composed of?
carbon, hydrogen, oxygen and nitrogen
What two things are somtimes present in proteins?
sulphur and phosphorus
Proteins are composed of?
amino acids
How many common amino acids are found in proteins?
20
How do amino acids bond together?
peptide bonds
What do proteins do to form a 3D shape?
proteins are folded
Chain of 20 or less amino acids = ?
Chain of more than 20 amino acids = ?
= polypeptide
= protein
Peptides join together to form?
polypeptides
Comment on the folding of fibrous proteins.
show little or no folding
Comment on the folding of globular proteins.
lots of folding
Comment on the shape of fibrous proteins.
rounded shapes
Comment on the shape of globular proteins.
unrounded shapes
What are 3 examples of fibrous proteins?
collagen: in bones and tendons
keratin: in hair and nails
myosin: in muscle
What are 3 examples of globular proteins?
enzymes
hormones
haemoglobin (protein found on red blood cells)
Give some metabolic roles of proteins.
enzymes: proteins make up enzymes for metabolic reactions.
hormones: regulate body reactions.
antibodies: fight infection
What is a structural role of proteins?
keratin in hair and nails
What are the 2 types of vitamins?
fat soluble, water soluble
Name a water-soluble vitamin.
vitamin C
Sources of vitamin C?
citrus fruits like lemons or oranges
Functions of vitamin C?
formation of connective tissues.
growth and maintenance of bones and teeth.
Disease caused by deficiency of vitamin C?
scurvy
Symptoms of scurvy?
bleeding gums, loose teeth
Name a fat-soluble vitamin.
vitamin D
Sources of vitamin D?
cod liver oil, dairy, eggs, (sunlight)
Functions of vitamin D?
absorbs calcium for bone and tooth formation
Disease caused by deficiency of vitamin D?
rickets (children)
Symptoms of scurvy?
weak, deformed bones that tend to break easily
Minerals are required in what amount size?
small amounts
Name 2 minerals required by animals, a source and their function.
calcium (milk, cheese): helps form strong bones and teeth
iron (red meat, green vegetables): helps form haemoglobin
Name 2 minerals required by plants, a source and their function.
magnesium (soil): formation of chlorophyll
calcium (soil): helps cell walls to attach to each other
Minerals are absorbed in form of dissolved salts including? (5)
calcium
magnesium
sodium
chlorine
potassium
Water makes up what % of cell mass?
70-95%
Functions of water?
- transport medium (heat, minerals, nutrients
- acts as a solvent
- acts as a reaction medium
Definition of metabolism?
the sum of all chemical reactions that take place in an organism
What are the 2 types of reactions?
anabolic, catabolic
Defintion of anabolic reaction?
forming large molecules from small molecules, using energy
Definition of catabolic reaction?
breaking down large molecules to small molecules, releasing energy
Give 2 examples of anabolic reactions.
protein synthesis
photosynthesis
Give 2 examples of catabolic reactions.
respiration
digestion
