Biological Molecules Flashcards
What is gen formula of carbs?
C6H12O6
What is the function of glucose?
Energy source
What is the function of glycogen?
Energy storage
What is glycosylation?
Sugars added to cell surface proteins - important aspect of the structure as they can differ as diff gly species attached to diff mol
What is the name of a sugar with 3 Cs and 2 e.gs?
Triose - e.g. glyceraldehyde, dihydroxyacetone
What is name of sugar with 5 Cs and e.g?
Pentose - ribose (in DNA + RNA)
What is name of sugar with 6 Cs and 2 e.g.s?
Hexose - e.g. glucose, fructose
What are aldoses and e.g?
Carbs containing aldose group e.g glucose
What are ketoses and e.g?
Carbs containing ketone group e.g. fructose
In terms of optical isomers, which sugars do humans use?
D-sugars
Which is C1?
carbon at the end closest to the carbonyl group
What % of hexoses are in linear form?
1%
What is the anomeric C?
Carbon attached to the original carbonyl group in cyclic form
What is the alpha form of glucose?
–OH group on the anomeric carbon in the down position
What is the beta form of glucose?
–OH group on the anomeric carbon in the up pos
Why are alpha/beta forms important?
glycosidic bond formation between sugars
What are alpha/beta forms like in solution?
α and β forms are in equilibrium and interconvert
What is a disaccharide and 3.e.gs?
2 monosaccharides joined together
e.g. sucrose (glucose + fructose)
– maltose (glucose + glucose)
– lactose (galactose + glucose)
What is a polysaccharide and 2 e.g.s?
Many mono
glycogen (branched chain glucose polymer)
– amylose (linear glucose polymer)
What is the structure of glycogen?
Linear glucose polymer α(1,4) with α(1,6) branches
What is the process of glycogen digestion?
1 glucose removed from 1 end + enz act on ends
Salivary α-amylase random hydrolysis of internal α(1,4) linkages
– Continues by pancreatic α-amylase mixture of mono- and disaccharides
– Finally maltase produces glucose be absorbed by the intestinal mucosal cells
What does Mobilisation of glycogen in liver involve?
Glycogen phosphorylase hydrolyses terminal α(1,4) to produce glucose-1-phosphate
What is lactose intolerance and what is it caused by?
can’t metabolise lactose correctly
• Normally in small intestine lactase (β-galactosidase) lactose → galactose and glucose
Red activity of b-galactosidase
• undigested lactose can then be digested by bacteria in large intestine producing excess carbon dioxide and other metabolites that cause bloating, diarrhoea etc
What are nucleic acids?
Polymers of nucleotides