Lecture 4- Lipids

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Created by emma_moran over 7 years ago


Biology- Semester 1 (Lecture 4- Lipids ) Flashcards on Lecture 4- Lipids , created by emma_moran on 12/21/2013.

Resource summary

Question Answer
Are lipids polar? No they are non-polar
Are lipids soluble in water? No they are insoluble
Are lipids soluble in non-polar solvents? Yes
Are lipids polymers? No
Structure of a triglyceride molecule Glycerol forms the backbone and 3 fatty acid side chains are attached to the glycerol backbone
What reaction occurs in the formation of triglycerides? Dehydration synthesis (condensation reaction)
Which enzyme catalyses the hydrolysis of triglycerides? Lipase
The possible products formed in the digestion of a triglyceride Glycerol, Diglyceride, Monoglyceride and Fatty acids
What are the features of a saturated fatty acid? Saturated with single C-C bonds. Solid at room temperature (closely packed)
What are the features of unsaturated fatty acids? Unsaturated with numbers of C=C bonds. Liquid at room temperature (loosely packed)
What are the two isomers that unsaturated fatty acids exist as ? cis- and trans- isomers
What is the difference between cis- and trans- isomers? Cis- isomers: bend at the double bond and are naturally occurring Trans- isomers: straight at the double bond and are normally manmade
This is a cis- fatty acid
Trans- fatty acid
What are fatty acids called when not part of a triglyceride? Free fatty acids
Omega 3 fatty acid
Omega 6 fatty acid
Steroids are lipids. What is the building block for other steroids?
How is lanosterol formed? The cyclization of squalene
Name some common steroids Cholesterol, oestrogen, progesterone, testosterone corticosteroids (produced in the adrenal cortex)
The structure of phospholipids The phosphate head (polar, hydrophilic, soluble in water), Fatty acid tails (non-soluble in water, non-polar and hydrophobic), glycerol backbone
Glycolipids Lipid attached to an oligosaccharide
Lipoproteins Soluble complexes that transport lipids and are usually synthesised in the liver
Structure of lipoproteins Spherical particles with central hydrophobic core: triglycerides, esterified cholesterol, small amounts of other lipids and fat soluble vitamins. External hydrophilic layer: phospholipids, cholesterol, apoproteins (stabilise the structure and regulate enzymatic activity at the lipoprotein)
Functions of white adipose tissue Cushions internal organs, acts as a shock absorber, gives insulation, protects internal organs from temperature swings
Effects of having excess adipose tissue Atheroma, atherosclerosis, thrombosis, exerts undue pressure on organs, sequestration (accumulation) of lipophillic substances
What is myelin? It is an insulating material, made from phospholipids, surrounds nerve cells
What cells produce myelin peripherally (nerves outside the brain and spinal cord)? Schwann cells
What cells produce myelin centrally (nerves in the brain and spinal chord)? Oligodendrocytes
Which vitamins are fat soluble? ADEK
What is the function of apoproteins? They provide structural stability and regulate enzyme activity in lipoproteins
What effect does myelin have on nerve cells? Increases the speed at which nerve impulses are transmitted along the nerve
How can lipids prevent moisture loss? They prevent the evaporation of water
Schwann cell
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Lecture 2- Introduction to Biological Molecules
Tutorial 3- Cell Cycle and Mitosis
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Lecture 10- Protein Synthesis
Lecture 3- Carbohydrates
Lecture 10- Translation
Lecture 2- Functional Groups
Lectures 11 & 12- Enzymes
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