These questions test your knowledge of lipid and carbohydrate structure and function
Reviewed by Jonathan Loomes-Vrdoljak on 25 July 2019
Which of the following macromolecules is incorrectly matched to its function?
Carbohydrates - quick energy source
Lipids - hormonal signalling
Proteins - enzymes
Nucleic acids - quick energy source
If cellulose is a carbohydrate, why can it not be used for quick energy in humans?
It is used for quick energy, but it is normally present in dense polysaccharide chains, which make it hard to be broken down
Humans lack the enzyme to break down beta-glycosidic linkages present in cellulose
It is used for quick energy, but its breakdown product can also be used as fibre
It is actually a protein
What is the generic molecular formula for carbohydrates?
[C(H2O)]n , with n≥3
[C(H2O)]n-2 , with n≥3
[C(H2O)]n-2 , with n≥4
[C(H2O)]n-2 , with n≥5
Lactase is a brush border enzyme in the small intestine. It is absent in people with lactose intolerance. The enzyme hydrolyses lactose into which of the following 2 monomers?
Glucose and fructose
Glucose and mannose
Glucose and galactose
Fructose and galactose
Which of the following disaccharide constituents are incorrect?
Lactulose (laxative) = galactose + fructose
Sucrose (table sugar) = glucose + galactose
Lactose (sugar found in cow’s milk) = glucose + galactose
Maltose (product of starch breakdown) = glucose + glucose
You request for your patient to have a fasting blood test. What is the name of the extensively branched polysaccharide produced by the liver whose monomers are released during the fasting state to maintain energy levels?
What is the composition of triglycerides?
Glycerol and a carboxylic acid
Glycerol and 3 fatty acids
Glycerol and 3 polysaccharides
A polysaccharide and 3 fatty acids
In what form is fat stored in adipose tissue?
What fat forms the main constituent of a cell's plasma membrane?
Your patient has dangerously low levels of cholesterol. How would you expect their cell membrane to behave?
It would be rigid as cholesterol adds extra fluidity to the membrane
It would be more fluid as cholesterol adds structural support to the membrane
Permeability would decrease because the other membrane molecules can pack closer together
Membrane surface receptors would be affected
What is a ketone body?
An altered amino acid formed by the metabolism of proteins released from muscle in starvation mode
A protein formed from glycogen in the liver when the body is not receiving sufficient glucose
3-4 polar carbon chain formed by beta oxidation of fatty acids in the liver.
A product of the breakdown of glycogen
You are doing a history on a patient when you notice a sweet smell of pear drops on their breath. What compound can this be?
Fructose - they must have eaten a pear before the consultation
Glucose - salivary amylase can break down polysaccharide chains beginning in the mouth
Ketone body - a volatile compound produced by the liver through beta oxidation of fatty acids.
Lactose - they lack the enzyme normally present in the mouth to break down this compound
Which of the following energy sources does not match where it is consumed?
Glucose - most tissues, brain
Fatty acids - most tissues except the brain
Ketones - most tissues, including the brain, but not the liver
Amino acids - most tissues
When can triglyceride storage be pathological?
When it spills into ectopic tissue
When it can be broken down into glycerol and free fatty acids
If it is stored for too long it can ferment
When storage balances utilisation
Which of the following glucose transporters are insulin sensitive?
A mutation in the gene that codes for the GLUT3 protein will have the largest impact on which cells?
Beta cells of the pancreas
Alpha cells of the pancreas
Which of the following glucose transporters are found in the kidney?
Which glucose transporter uses secondary active transport to move glucose across the cell membrane?