Biological molecules Flashcards
`the biochemical basis of life is…
similar for all living things
monomers are
the smaller units of which larger things are made
polymers are
molecules from which many monomers are joined together
3 examples of monomers
amino acids, monosaccharides and nucleotides
What does a condensation reaction do?
join two molecules together
What is formed in a condensation reaction?
a chemical bond
What is eliminated in a condensation reaction
a molecule of water
What is a hydrolysis reaction?
the breaking of a chemical bond between two molecules
3 common monosaccharides
glucose, fructose and galactose
What is used during a hydrolysis reaction
water
What does a condensation reaction between two monosaccharides form?
a glycosidic bond
3 examples of disaccharides
Maltose, sucrose, lactose
maltose formation
two glucose molecules
sucrose formation
a glucose molecule and fructose molecule
lactose
a glucose molecule and galactose molecule
Is starch soluble
No starch is insoluble
Is starch large
Yes
Is starch compact
yes
Starch structure and its purpose
Branched form so multiple enzymes can act upon it at once to release glucose quickly
What is starch made up of?
Amylose and amylopectin
Cellulose is made of…
Beta glucose
Cellulose has a ______ structure
Straight chain
Cellulose forms ____ glycosidic bonds
1-4
Cellulose is un…
Branched
Cellulose has micro/macro…
Fibrils
Glycogen is made of…
Alpha glucose
Glycogen has a _____ structure
Branched
Glycogen forms ___ and ___ glycosidic bonds
1-4, 1-6
Glycogen is..
Coiled
What is the use of starch being insoluble
The water potential is not affected
What is the use of starch being coiled
The molecule is compact
What is the use of starch being a polymer of alpha glucose
Glucose can be used in respiration
What are the two types of lipids?
Triglycerides and phospholipids
What does a condensation between a glycerol and fatty acid molecule form?
An ester bond
What are fatty acids with a single double bonds present called?
Mono-unsaturated
What are fatty acids with multiple double bonds called?
Poly-unsaturated
More double bonds in the hydrocarbon chain…
The more the hydrocarbon bends
How does the smaller proportion of oxygen to carbon and hydrogen relate to triglyceride function?
More carbon to hydrogen bonds, so lipids are a good source of energy
How does the low mass: energy ratio of triglycerides relate to their function?
They are good for storage as it can be stored in small volumes
How does the large and non polarness of triglycerides relate to their function?
They are insoluble so won’t affect the water potential of the cells
How does the high ratio of hydrogen: oxygen relate to function of triglycerides?
They release a lot of water molecules when oxidised
What is an example of a non reducing sugar?
Sucrose
What are the extra steps to the non reducing sugars test?
Add hydrochloric acid and heat in a water bath
Allow to cool
Add sodium hydrogen carbonate and wait for fizzing to stop
Do reducing sugars test
Why do you heat sucrose with hydrochloric acid during non reducing sugars test?
To hydrolyse the sucrose and break the glycosidic bonds between glucose and fructose
Why is sodium hydrogen carbonate added to the non reducing sugars test?
To neutralise the hydrochloric acid
What is a property of water that makes it helpful for reactions?
It is a metabolite in condensation/ hydrolysis reactions
Why is water having a high specific heat capacity important for organisms?
It buffers changes in temperature of the body
Why is water being a solvent useful?
Metabolic reactions can occur
Why is water having a large latent heat of vapourisation useful for organisms?
There is a cooling effect through evaporation
Why is water having cohesion important for organisms? 1
Supports columns of water (transpiration)
Why is water having cohesion important for organisms? 2
Produces surface tension
Describe competitive inhibition
-the inhibitor has a similar shape to the substrate so enters the active site
-the substrate can no longer bind to the active site more frequently
-so fewer ESC’s form
-decreasing the rate of reaction
-this can be overcome by adding more substrate
Describe non competitive inhibition
The inhibitor binds to the enzyme (not the active site)
This changes the shape of the active site
Which prevents the substrate binding as it is no longer complimentary
This cannot be overcome by adding more substrate
Explain why an enzyme only catalyses one reaction
The tertiary structure means the enzyme’s active site is only complimentary to a specific substrate
Example question: explain why Maltase only breaks down maltose and why this happens at room temperature
The tertiary structure of Maltase means its active site is complimentary to only the substrate of maltose
The active site of Maltase changes slightly to accommodate the substrate
The enzyme lowers the activation energy by forming ESC’s
What is a nucleotide formed from?
A phosphate group, a pentose sugar and a nitrogenous base
What does a condensation reaction between two nucleotides form?
A phosphodiester bond
Where does the phosphodiester bond between two nucleotides form?
Between the phosphate group and a pentose sugar
