Biological Molecules Flashcards
What is the general formula of carbohydrates?
(CH₂O)n
Describe what is meant by a monosaccharide
A single monomer saccharide e.g. Glucose
List some features of a glucose molecule
- 6 Carbon molecule (hexose sugar)
- ɒ and β glucose (OH on C1)
- Aldose sugar
- Has 4 chiral centres
- Has an enantiomer (is optically active)
What are the two structural types of sugars?
Ketone based
CH2(OH)COCH2OH
ketose sugar
Aldehyde based
CHOCHOHCH2OH
aldose sugar
What are the two enantiomers of sugars?
D or L
determined by the OH on the 5th Carbon being either on the left (L) or the right (D)
How are disaccharides formed?
Via condensation reactions forming Glycosidic bonds between sugar molecules
What are some features of Glycogen?
- Branched
- 1-4 ɒ Glycosidic bonds
- 1-6 ɒ Glycosidic bonds
- Easily broken down by enzymes
- Aldose sugar
List the structural features of Starch
- 1-4 ɒ bonds
- not branched
What is an oligosaccharide?
Saccharide polymers made of small numbers of monosaccharides and lipids
Give an example of oligosaccharides
ABO blood groups
What does the structure of an amino acid comprise of?
- Amine group NH
- Carboxyl group COO
- Variable side chain (R group)
List some features of amino acid structure?
- 20 amino acids
- central carbon is chiral
- L-amino acids in organisms
(bacteria cell walls made of D amino acids)
What are amino acids the precursors of?
“Hormones
e. g.
- Tyrosine -> adrenaline
- Histidine -> Histamine”
What are the components of a nucleotide?
- Sugar
- Phosphate
- Nitrogenous base
List the structural differences between RNA and DNA
RNA
- ribose sugar
- A, U, G, C bases
- single stranded
DNA
- deoxyribose sugar
- A, T. G, C bases
- double stranded
How is the DNA backbone formed?
“Nucleic acids made in a 5’ - 3’ direction, joining to alternating sugar
and phosphate molecules “
Why is DNA more stable than RNA?
A single oxygen difference
What are body fats made of?
Glycerol esters of fatty acids (triglycerides)
Explain the structure of a phospholipid
Glycerol ester of two fatty acids and 1 phosphate group
What is the arrangement of phospholipids in membranes?
Hydrophilic head sits on outside of the membrane
Hydrophobic tails hidden intracellularly
When are micelles formed?
When phospholipids are submerged in water they form micelles
How do proteins become non functional?
If proteins lose their structures due to mutations or denaturing
Describe the effects of 3 single molecule diseases
Diabetes
- insulin dependent
- leads to failure of blood glucose regulation
Sickle cell disease
- haemoglobin aggregates into polymers
- due to change in 1 amino acid in a globulin chain
Cystic fibrosis
- absence of chloride ion transport protein
- leads to altered secretions
