Biomolecules & Amino Acids Flashcards
Name the major families of Biomolecules
hint- there are 8
Carbohydrates, nucleic acids, Lipids, Proteins, Cholesterol / Steroid Hormones/ Vitamins/ Co factors/ Xenobiotics
What is the general formula for carbohydrates
(CH 2 ) n
What is the function of carbohydrates, giving examples?
Energy source- glucose
Energy storage- glycogen
Structural- part of cell wall in bacteria - peptidoglycan
Cell Surface proteins can often be glycosylated- ABO blood groups
What is the definition of isomers?
Same chemical group but different arrangement of atoms in the molecule
What is the difference between aldoses and kotoses
Aldoses have the functional group aldehyde - glucose
Ketoses have the functional group ketone - fructose
What is the anomeric carbon
Carbon attached to the original carbonyl group in cyclic form is the anomeric carbon
What is the difference between alpha and beta glucose? And explain why the difference is important.
The OH group on the anomeric carbon in alpha glucose is down the plan whilst is up the plane in beta glucose.
This is important due to the formation of glycosidic bonds
Sucrose =
Maltose =
Lactose=
glucose + fructose
2 x alpha glucose
glucose + galactose
What is the difference between glycogen and amylase?
glycogen is branched and amylase is more linear
Describe the structure of glycogen.
Linear alpha glucose molecule with alpha-1,4 and alpha-1,6 branches. This is beneficial because more branches means more terminal ends- this increases the number of sites for enzymes which act on terminal ends. Therefore more glucose can be converted form glycogen.
Describe the digestion of glycogen
Salivary alpha amylase hydrolyses random alpha-1,4
Pancreatic alpha amylase hydrolyses to a mix of mono and di
Maltase hydrolyses maltose into glucose which is easily absorbed by intestinal mucusoal cells
Comment on lactose Intolerance
Normally lactose is broken down by lactase into glucose and galactose in the small intestine. ( membrane bound)
However not possible in people lacking the enzyme-
undigested lactose is then digested by bacteria in the large intestine releasing CO2 and other metabolites.
What are nucleotides made up of ?
Pentose sugar
Phosphate
Nitrogenous Base
What are the functions of polymers of nucleotides?
Store genetic information (DNA)
Convert genetic information into proteins (RNA)
Describe DNA structure
Helical structure Long polymer of nucleotides Sugar Phosphate backbone Two strands are antiparralel The strands are complementary due to H bonds forming between comp base Pairs
Contrast the structure of DNA and RNA
RNA is smaller and single stranded
Explain the function of mRNA
it is a copy of a gene hence provides the template for protein synthesis
Explain the function of rRNA
acts a structural component to ribosomes
Explain the function of tRNA
Transports the AA to the the ribosome that is complementary to the codon on the mRNA sequence. This ensures that the correct sequence of amino acids is coded for
Why is ATP a highly useful molecule?
high energy bond between Pi
the bond is readily hydrolysed
This means that the energy released can be used to drive metabolic reactions which are not usually thermodynamically feasible.
Describe Triaglycerols
It is a hydrophobic molecule
3 fatty acids and 1 glycerol
Ester bond between the glycerol and fatty acid components
Used mainly for energy storage- stored in adipose tissue
The fatty acids can be saturated, unsaturated etc
What are the types of fatty acids? ( Hint- 4 types)
Non esterfied fatty acid- eg long chain aliphatic carboxylic acids. These can also be metabolised via beta oxidation pathway to generate ATP
Saturated- eg stearic acid
Unsaturated- eg oleic acid
Polyunsaturated- eg linoleic acid
What is meant by the term amphipathic?
eg. phospholipids- polar head, non polar tail.
Useful in forming a membrane
What defines Steroids?
4 Rings of a biologically active organic compound
eg. Steroids- from diet or de novo ( plays an important role in membrane fluidity )
