Food (Biomolecules) Flashcards
3 functions of food
provide energy
growth of new cells and repair of damaged cells
make molecules that control metabolism
what does food need to provide energy for? 2
metabolism and production of heat
what is growth of new cells needed for?
for continuity
2 molecules that control metabolism
enzymes
hormones
6 common elements in food
carbon hydrogen oxygen nitrogen phosphorous sulfur
5 elements present in dissolved salts
sodium clorine potassium calcium magnesium
3 trace elements in food
iron
copper
zinc
6 biomolecular components of a balanced diet
carbohydrates proteins lipids vitamins minerals water
biomolecules
molecules found in living organisms
2 types of carbohydrates
sugars and starches
component elements of carbohydrates
carbon, oxygen and hydrogen
formula for carbohydrates
Cx(H2O)y
glucose formula
C6H12O6
ratio of hydrogen:oxygen in carbohydrates
2H:1O
the smallest unit of a carbohydrate
saccharide
monosaccharide
one sugar unit
disaccharide
two sugar units linked together
polysaccharide
many sugar units linked together
use of monosaccharides
in respiration for the release of energy
2 examples of monosaccharides
glucose
fructose
are monosaccharides reducing sugars?
yes, all are
use of disaccharides
broken down easily to monosaccharides and used for the release of energy
3 common disaccharides
sucrose
lactose
maltose
where do you find sucrose
table sugar
where do you find lactose
in milk
where do you find maltose
formed during the breakdown of strach
sucrose is made of
glucose and fructose
lactose is made of
glucose and galactose
maltose is made of
2 glucoses
2 functions of polysaccharides
to store energy
used as structural material
2 polysaccharides that store energy
starch
glycogen
2 polysaccharides used as structural material
cellulose/chitin
what is starch made of
long chains of glucose molecules, folded and packed into starch grains
function of starch
stores energy in plants
3 sources of starch
potatoes
bread
rice
what is glycogen made of
made of long chain of glucose molecules
function of glycogen
stores energy in animals
what is the other name of glycogen
animal starch
where is glycogen found 2
liver and muscle
what is cellulose made of?
many long chains of glucose molecules
structural function of cellulose
forms cell wall in plants
function of cell wall
gives shape and strength to the cell
can humans digest cellulose
no
why is cellulose important in our diet
as roughage as fibre
function of fibre
fibre adds bulk to the waste in the gut and stimulates peristalsis
helps to empty the gut faster
what does lack of roughage do
causes constipation
2 places where chitin is stored
found in the exoskeleton of arthropods
in the cell wall of fungi
composition of protein
carbon
hyrogen
oxygen
nitrogen
what can some proteins also contain
sulphur and other elements
units of protein
amino acids
how many commonly occuring amino acids found in proteins
20
how do amino acids form a proetin
they are joined in chains by peptide bonds
peptide
chain of less than 20 amino acids
polypeptide
chain of more than 20 amino acids
are proteins polypeptides
yes
what differs different proteins
the number and sequence of amino acids
sources of protein
eggs
soya beans
5 functions of protein
cell membranes enzymes and hormones haemoglobin antibodies muscle,skin etc.
denaturing
change in structure with a loss of water
denaturation of protein
an irreversible change in the structure of a protein, so that it can no longer function
3 ways you can denature a protein
strong heat
pH too high or low
organic solvents
can plants store protein
yes
where do plants store protein
eg.in stem and root tubers
can animals store protein
no
what happens to excess protein in animals?
broken down in the liver and converted into urea
deamination
3 types of lipids
fats, oils, waxes
composition of lipids (elements)
carbon, hydrogen, oxygen
composition of lipids
one glycerol and 3 fatty acids
what are lipids called
tryglyceride
fats
lipids that are solid at room temperature
oils
lipids that are liquid at room temperature
phospholipids
lipids where one of the fatty acids is replaced by a phosphate group
3 sources of lipids
oil, nuts, avocado
functions of lipids
release and storage of energy formation of cell membranes forms adipose tissue under the skin protection of internal organs formation of vitamin D sebum prevents dry and cracking of skin forms some hormones wax is used as waterproofing material in plants and animals
what are vitamins
complex organic compounds found in very small quantities in natural food
do vitamins have energy value
they have no energy value but are essential for the good health of the body
what makes vitamins?
plants make vitamins, but animals must get them in their food
1 fat soluble vitamin
D
main sources of vitamin D
egg yolk, milk, action of sunlight on lipid in skin
function of vitamin D
to absorb calcium from intestines into the blood
2 deficiency diseases of vitamin D
rickets in children
osteomalacia in adults
water soluble vitamin
Vitamin C
main sources of Vitamin C
citrus fruits
berries
green vegetables
function of Vitamin C
formation of skin, gums, bones, blood vessels
deficiency diseases of Vitamin C
scurvy
2 symptoms of scurvy
bleeding gums
slow wound healing
structural role of carbohydrate
cellulose in cell wall
structural role of proteins
fibrous
keratin in hair
myosin in muscle
collagen in skin
structural roles of lipids
phospholipids in cell
protective layer around organs eg.kidneys
metabolic roles of carbohydrates 2
release of energy (eg.glucose)
storage of energy (starch (plants) glycogen (animals))
metabolic roles of proteins 2
formation of enzymes (control all metabolic activity)
formation of some hormones (eg.insulin)
metabolic role of vitamin c
needed for the formation of the skin, bone, cartilage, gums and lining of blood vessels
minerals
inorganic chemicals
note on energy of minerals
have no energy value but are need in small amounts, essential for good health
4 functions of minerals in living organisms
form rigid body structures eg. calcium in bones and cell walls
form soft body tissues eg. nitrogen and sulphur in muscles
form cell and body fluids eg. sodium in blood plasma
formation of pigments eg.iron in haemoglobin
2 animal minerals
calcium and iron
sources of calcium
milk
hard water
functions of calcium
bone and tooth formation
calcium deficiency symptoms
poor bone growth
rickets
sources of iron
liver, red meat, spinach
functions of iron
forms part of haemoglobin
deficiency of iron
anaemia (not enough haemoglobin)
2 plant minerals
calcium
magnesium
sources of calcium plants
absorbed from soil
functions of calcium plants
forms middle lamella between cell walls
deficiency of calcium plants
death of growing tips
sources of magnesium
absorbed from soil
function of magnesium
forms part of chlorophyll
magnesium deficiency
yellow leaves
7 importances of water in living organisms
good solvent chemical reactions turgor moves easily in and out of cells absorbs energy strong cohesion major component of cytoplasm and body fluids
explain water as a good solvent
in chemical reactions in the cytoplasm and a transport medium in blood, lymph, xylem and phloem
explain how water takes place in chemical reactions
in photosynthesis, water provides hydrogen to make carbohydrates
how does water give turgor
non woody (herbaceus) plants need h2o for turgor to support the plant or else the plant wilts
explain how water moves easily in and out of cells is important
allows substances dissolved in water to move in and out of cells
explain how water can absorb energy is important
it takes a lot of energy to heat it up (high specific heat capacity) heats up slowly, cools down slowly. high water content allows for stable temperature in an organism
explain strong cohesion of water
the upward movement of h2o in plants is helped by strong cohesion (attraction) of h2o molecules
