Biomolecules Flashcards
(31 cards)
Structures of amino acid
Primary - the sequence of amino acids in a polypeptide chain
secondary - consist of the two structures, alpha helix and beta pleated sheets
Tertiary - the secondary structure further folded into a 3-D shape
Quaternary - a combination of two or more polypeptide chains held in a higher level of protein structure
What is meant by hydrolysis?
the addition of water molecules to break the bond
What is condensation?
The removal of a water molecule to form a bond
The three enzymes involved in the complete hydrolysis of starch
Starch is digested to maltose by amylase
Maltose is digested to glucose by maltase
Isomaltase breaks the amylopectin at the branch points
What happens if more amylopectin is present?
More amylopectin present means that more ends can be digested. They are also less tightly packed so easier to digest.
How does the structure of cellulose provide support?
Alternative molecules of beta glucose rotate through 180° to microfibrils
This provides strength to the cell wall
Non-reducing sugars test
Heat both solutions with acid then neutralise them with alkali then heat with Benedict’s
If non-reducing sugar is present a colour change from blue to brick red will occur
Protein test
Add biuret solution to a sample of both solutions
If protein is present a colour change will occur from blue to lilac
Bond formed in a condensation reaction of amino acids
Peptide bond
How is secondary structure maintained?
Hydrogen bonding
Why do some mRNA molecules have a higher molecular mass than others
Pre-mRNA contains both Intron and exons
The entire gene is transcribed
Introns are non-coding and Exons are coding
The pre-MRA is then edited to remove the introns
Pre-edited pre-mRNA molecules and post edited mRNA molecules have different masses
Only the edited mRNA is used in translation
Structure of starch six points
Polymer of alpha glucose
Composed of amylose and amylopectin
Amylose contains only one to 4 glycosidic bonds
Forms a helical structure
Amylopectin contains one, four and one, six glycosidic bonds
Forms a branched structure
Structure of triglycerides 4
Composed of glycerol and 3 fatty acid
Joined together by ester Bond
Saturated fatty acids only contain C-C single bonds
Unsaturated fatty acids contain at least one C=C double bond
Functions of starch in the seed
Starch is insoluble so are osmotically inert
Starch helical/branched structure makes the molecule compact
Hydrolysis provides glucose readily
Required for respiration/produce ATP
Functions of triglyceride in seeds
Insoluble so are osmotically inert
Have a compact structure
Have many high energy bonds provide approximately twice the quantity of energy than starch
Why the presence of unsaturated fatty acid in the phospholipid would increase fluidity of the membrane
Unsaturated contain double bonds between carbons
They produce a kink
Less packing is possible
Lowest intermolecular forces
Less energy needed to break the bonds
How a diet high in animal products and cholesterol can lead to a person developing heart disease
Raises levels of LDL
Increase incidence of atheroma in arteries
Define quaternary structure
Two or more polypeptide chains bonded together to form a functional protein
State the type of reaction that occurs when a molecule is broken down into two monosaccharides
Hydrolysis
Sulphur function
Required to synthesise some amino acids or proteins
Water properties - ice
Ice is less dense than water so it floats insulating the water below allowing organisms to survive
Water as a polar solvent
All chemical reactions occur in aqueous solution
Polar molecules and ions can dissolve and therefore be transported
Water as cohesive
Water molecules from hydrogen bonds allowing the movement of water
Two inorganic ions needed by plant cells in order to synthesise nucleotides
nitrate
Phosphate
