1A Flashcards
what is a monomer
small units from which a larger units are made from
what is a polymer
molecules made from a large number of monomers joined together
give an example of a monomer
monosaccharides-glucose, fructose or galactose
amino acids
nucleotides
give an example of a polymer
protein
starch
DNA
what is a condensation reaction
joining of 2 molecules with the formation pf a chemical bond and involves water as a bi-product
what is an example of a condensation reaction
glucose+fructose=sucrose+water
glucose+glucose=maltose+water
galactose+glucose=lactose+water
what is a hydrolysis reaction
breaking of a chemical bonds between 2 molecules and involves the use of a water molecules
what is an example of a hydrolysis reaction
lactose+water=galactose+glucose
what is an organic molecule
carbon containing molecules made up of:
-carbon
-hydrogen
-oxygen
-nitrogen
what are the 6 types of bonds, explain their formation and use
ionic-attraction between opposite charges- fairly strong cell membranes
disulphide- occurs during protein folding- stabilises protein/ catalyst
hydrogen- H+ ion- cellulose, b-sheets and DNA- very weak
ester- condensation reactions in lipids- 3 on tri- 2 on phos
peptide- condensation in proteins- one acid to carboxyl group
glycosidic- condensation of a-glucose and b-glucose- 1-4 and 1-6 bonds
explain how to do a test for reducing sugars
- 1cm3 of sample to a test tube
- add a few drops of Benedict’s solution
3.shake to mix - heat in boiling water form 5 minutes
- postive = blue to either green if its a low conc or red if a high conc
why does the Benedict solution change colour if its a reducing sugar
it has one carbon available which means it can donate electrons(reduce) to turn the colour
describe the test for non-reducing sugars
if non-reducing the benedicts won’t change colour so use this:
1. add 1cm3 of dilute hydrochloric acid to the test sample
2. gently place it into boiling water for 5 minutes
3. neutralise with sodium hydrocarbonate powder (test with ph strip)
4. do the Benedict’s test
describe the test for lipids
- add 2cm3 of sample into test tube
- add 5cm3 of ethanol
3.place bung in and mix then allow it to settle - pour the contense of the test tube into 5cm3 of distilled water
- if it is cloudy white it contains lipids
what should you always do before the emulsion test
- if sample is solid mix with ethanol or alcohol
- ensure test tubes are dry and clean
describe the test for starch
- add 2cm3 of test solution to a test tube
- add several drops of dilute iodine
3.shake to mix - positive result is brown to blue/black
describe the test for proteins
- prepare your sample
- add a few drops of Biuret solution
3.shake to mix - its positive if colour changes from blue to purple/violet
can you draw alpha glucose
CH2OH
H I________O H
I / |
OH \____________/OH
H. OH
can you draw beta glucose
CH2OH
OH I________O OH
I / |
H \____________/ H
H. OH
can you draw a condensation reaction
look up if you cant
what type of bond is formed between glucose
glycosidic
what is starch used for
energy store in plants
describe amylose
- 1-4 glycosidic bonds
- unbranched
-helical to allow it to be compact
describe amylopectin
- important to hydrolyse
- has a 1-6 glycosidic bond
-has branches - has a few 1-4 bonds
what are the properties of starch
insoluble- doesn’t affect water potential
large- doesn’t move out of the cell
-made from a-glucose so quick release energy
- branches allow rapid hydrolysis
what is the function of glycogen
quick release energy
what are so properties of glycogen
- made of a-glucose
- it has a 1-4 and 1-6 glycosidic bonds
- its branched and helical
- compact
- bonding makes it able to do its job
how is glycogen broken down
respiration or hydrolyses
what is the function of cellulose
strengthen cell walls
what are the properties of cellulose
- made from b glucose
-forms microfibrils - has hydrogen bonds in between each layer which makes it collectively strong
-its insoluble but allows water through osmosis - it has 1-4 glycosidic bonds
draw a cellulose molecule
each b-glucose molecule is inverted each time
what are the two types of lipids
phospholipids
triglycerides
what are some common traits off lipids
- each contain carbon, hydrogen and oxygen
-they are insoluble but sometimes soluble in alcohol - made of glycerol and fatty acids
what is the difference between a saturated and unsaturated lipid
saturated has no double bonds between carbon and can be compact
unsaturated has a double bond between carbon
what are the 2 types of unsaturated molecules
mono-unsaturated- single double bond
poly-unsaturated- has more than one double bond
what is a triglyceride made of
1 glycerol
3 fatty acids
what type of bond does a lipid form
an ester
draw the formation of a triglyceride
look at notes
draw an unsaturated and saturated lipid
look at notes
what are the properties of triglycerides
-strong- lots of bonds
-lightweight- compact
- large
-insoluble
- non polar
- releases water when oxidised
what is a phosopholipid made of
-phosphate head
- glycerol
- 2 fatty acid
how does a phospholipid use its hydrophilic head
it is used to create cell membranes as they form two layers where they attract water outside and inside this creates a layer
how does a phospholipid use its hydrophilic tail
it creates a bilayer plasma- the tail is used to protect vital hormones from water as it repels them
what is a protein used for
make up most things in the body- big 3D molecules
what is the sequence for proteins
amino acids -> peptide -> polypeptide
how many amino acids are their in the body
20
what is the first stage sequence
amino acids
what are the two groups in an amino acid
amino group
carboxylic group
draw an amino acid
look at notes
Name and describe the 5 stages of protein production
Amino acids
Primary - the sequence of amino acids in the polypeptide chain- determines shape/ function
Secondary- the chain is then folded into either a a-helix or a b-pleated sheet
Tertiary- once secondary is formed the molecule folds into a 3d shape- here it makes the 3 types of bonds ionic hydrogen and disulphide.
Quaternary- multiple protein molecules bind together to form a protein
What are the 2 types of tertiary structure
Globular- carries out metabolic function
Fibrosis- long chains which run Parallel to another these are linked by cross bridge
what is a enzyme
biological catalyst that catalyse metabolic reactions
protein
what do enzymes do
they lower the activation energy by provding an alternate pathway. this speeds up the rate of reaction
what is the lock and key theory
this is when the substrate only fits in the enzyme if its the same shape
what is the induced fit theory
this is when the substrate has to be the same shape as the active site then once in the active site it changes shape slightly to form enzyme-substrate complex
how do the enzymes get their properties
it relates to their tertiary structure. different shaped active site different function.
what are the factors effecting enzymes
temp
enzyme conc
substrate conc
ph
what happens to the enzyme activity if the temp is higher
the enzymes get more kinetic energy so they move faster. so more likely to collide with substrate so rate of reaction increases as more enzyme complex.
what happens if the temp is too high
the enzymes denature and the active site changes shape so nothing can fit in it and rate of reaction decreases
how does ph affect activity
When the pH value deviates from the ideal conditions, the activity of the enzyme slows down and then stops. The enzyme has an active site at the substrate binding site, and the shape of the active site will change with the change of pH value.
how is activity effected by enzyme conc
The higher the enzyme concentration, the more enzymes there are to form enzyme-substrate complexes, leading to an increase in enzyme activity. This happens up to a certain point. Enzyme activity then levels off (plateaus) as there are not enough substrate molecules to react with the extra enzymes.
how is activity effected by substrate conc
an increase in substrate concentration leads to an increase in the rate of an enzyme-catalyzed reaction. As the enzyme molecules become saturated with substrate, this increase in reaction rate levels off. The rate of an enzyme-catalyzed reaction increases with an increase in the concentration of an enzyme
what is a competitive inhibition
theses bind to the active site of the enzyme and stop any substrates from entering the active site so no substrate enzyme concs can form. rate of reaction can decrease
can you get rid of competitive inhibitors
yes
but not with higher substrate
what is a noncompetitive inhibitors
this is an inhibitor that binds somewhere other then the active site() this changes the shape of the active site so the enzyme can’t bind and make enzyme substrate complex.
can you remove the noncompetitive inhibitors
no
their is no way to change back the shape
what are the ways you can measure ROR
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