Biomolecules Flashcards
What are the X4 main groups of biomolecules?
1) amino acids
2) sugars
3) nucleotides
4) fatty acids
What blood test looks at glycosylated haemoglobin?
HBA1c
What is the Fischer projection?
How would you determine a D or L sugar from this projection?
It draws sugars in a linear form, with the most oxidised carbon at the top.
For D sugars, the OH group on lowest chiral centre carbon will be on the right hand side of the chain.
L sugars have the OH group on the left.
What type (D or L) of sugars and amino acids do humans use?
D-sugars
L-amino acids
What percentage of hexoses are in linear form at any one time?
<1%
What are the X2 forms of glucose that exist?
How are they different?
1) Alpha
= has the H on carbon 1 above
2) Beta
= has the H on carbon 1 below
What percentage of glucose is in the alpha or beta form at any one time?
They interconvert all the time between alpha to open chain to beta and back again…
What are the X3 monosaccharide sugars?
1) glucose
2) lactose
3) fructose
What are the X3 disaccharide sugars and which monosaccharides bind to form these?
1) maltose = alpha glucose + alpha glucose
2) galactose = glucose + lactose
3) sucrose = glucose + fructose
What bond links glucose in glycogen?
Alpha 1-4 glycosidic bonds with alpha 1-6 glyocosidic bond branches
Which enzyme is located at the brush boarder of the small intestine for glycogen breakdown when it has been broken down into a disaccharide?
Maltase
Explain lactose intolerance?
A lack of the lactose enzyme in the small intestine.
This means galactose travels through the small intestine without being broken down and can be digested by bacteria in the large intestine which produces CO2, hydrogen and methane.
What are the X3 components of a mononucleotide?
1 = pentose sugar 2 = nitrogenous base 3 = phosphate group
What are the X2 classes of bases?
Which bases belong to each of these?
Purines
= adenine
= guanine
Pyramidines
= cytosine
= thymine
What are the X2 types of pentose sugar and which is used in:
- DNA
- RNA
DNA = deoxyribose
RNA = ribose
What bond links nucleotides to form polynucleotides?
Phosphodiester bonds between the phosphate of one nucleotide and the pentose sugar of another
What is the orientation and structure of the X2 strands of DNA?
They run anti parallel in a double helix
Which bases undergo complementary base pairing?
How many bonds does each pair make?
A — T = X2 bonds
G — C = x3 bonds
What does the 3 or 5 prime end of a DNA strand actually refer to?
It refers to the number of the carbon in the sugar molecule at that end of the strand.
What are the x3 types of RNA?
What is the function of each?
1) mRNA
= a copy of a gene which enables the genes code to be copied to the ribosome for translation
2) rRNA
= structural component for ribosomes
3) tRNA
= transports amino acids for protein synthesis
What is gene expression?
The process by which information from a gene is used to synthesis a gene product
What are the X2 stages of gene expression?
1) transcription
= forming mRNA
2) translation
= synthesis of a protein based on the mRNA
What is the structure of a TAG?
What bonds are formed in the synthesis of a TAG?
X1 glycerol molecule
X3 fatty acid chains
Ester bonds
What is the structure of a phospholipid?
X1 glycerol molecule
X2 fatty acids chains
X1 phosphate group
