Unit 1 - Biological Molecules Flashcards
why is water a polar molecule
the oxygen has a small negative charge
and the hydrogen have a small positive charge
what bond joins water molecules together
hydrogen bond
(they are weak)
what is meant by specific heat capacity
the amount of energy needed to change 1kg of something by 1 degree
does water have a high or low SHC
very high
what happens when you heat water / try to change the SHC
the heat energy goes towards weakening or breaking the hydrogen bonds
what is meant by water being a good solvent
lots of substances can dissolve in water
what is an advantage to water being a good solvent
it can be used to transport substances
what is it called when water molecules stick together
cohesion
what is an advantage to cohesion
large collums of water can travel in the xylem
examples of a metabolic reaction
photosynthesis
aerobic respiration
give 2 examples of carbohydrates
sugar
starch
what is a hexose sugar
a sugar with six carbon atoms
what is a monosaccharide
a single sugar molecule
give 3 examples of monosaccharides
glucose
galactose
fructose
are monosaccharides soluble in water
yes
what does hydrophillic mean
-water loving
-dissolves in water
what is a pentose monosaccharide
a monosaccharide with 5 carbon atoms
give an example of a pentose monosaccharide
ribose
what is a disaccharide
when 2 monosaccharides are chemically joined
what is a polysaccharide
3 or more monosaccharides chemically joined
if the OH group is on the bottom which isomer of glucose is it
alpha glucose
if the OH group is on the top which isomer of glucose is it
beta glucose
what type of bond is formed when alpha glucose is joined
glycosidic
is glucose soluble in water and why
yes, extremely
because it has a large amount of hydroxyll groups
how do plant cells store glucose
as starch
what is amylose
a polymer of alpha glucose molecules
what shape is amylose and why is it benefical
its a helix shape so its very compact
how is amylopectin different to amylose structually
amylopectin is branched whereas amylose isnt
is starch soluble in water and how does it help its function
its not soluble which means it doesnt cause water to enter the cell by osmosis
how is cellulose stong
hydrogen bonds form between its straight chains
what bond joins amino acids together
peptide bond
what is the role of ribosomes
site of protein synthesis
what is it called when you join 3 or more amino acids
a polypeptide
how can you change the tertiary structure of an enzyme
by heating it as the shape of the active site has changed
what is meant by the tertiary structure of a protein
the 3 dimensional arrangement of its polypeptide chain
what is the quaternary structure of a protein
shows us how the subunits fit together to form a larger structure
features of a globular protein
- spherical shape
- soluble in water
why are globular proteins soluble in water
they have hydrophillic amino acids on their surface
where are the hydrophobic amino acids in a globular protein
in the centre
give 3 examples of a globular protein
haemoglobin
insulin
lysozyme
what is the role of haemoglobin
to bind to oxygen in the lungs
how does haemoglobins featres make it seful for its purpose
haemoglobin has 4 haem molecules and 1 haem molecule binds to 1 oxygen molecule so each haemoglonin molecule can carry 4 oxygen molecules
how do hormones carry out their function
by binding to specific receptor molecules
where is lysozymes found
saliva and tears
what are functions of globular proteins
enzymes
hormones
oxygen carrying proteins
what are the functions of fibrous proteins
structural proteins like in
bones
or walls of arteries
what is the structure of a fibrous protein
long rope like molecules
features of fibrous proteins
- long rope like
- insoluble in water
give 3 examples of fibrous proteins
collagen
keratin
elastin
what is the structure of a triglyceride
1 glycerol
3 fatty acids
what bonds hold glycerol and fatty acids together
ester bonds
what does the enzyme lipase do in the digestive system
breaks down the ester bonds of a triglyceride so you get glycerol and 3 fatty acids
are triglycerides polar or non polar
non polar meaning theyre hydrophobic so they dont dissolve in water
what is the structure of a phospholipid
1 glycerol
2 fatty acids
and a phosphate group
why is a phospolipid partially hydrophillic
because the phosphate group is negatively charged so is hydrophillic but the fatty acids are hydrophobic
what is a phospholipid bilayer
when the phospholipids position themselves so the phosphate group interacts with water but the fatty acids dont
what is a monomer
small units which larger molecules are made from
what is a polymer
molecules made from a large number of monomers
