Biochemistry Flashcards
What are Short Chain Fatty Acids (SCFA)?
They are volatile 2-5C FA
Polar
Common name for Ethanoic Acid (2C)
Acetic Acid
Common name for Propanoic Acid (3C)
Propionic Acid
Common name for Butanoic Acid (4C)
Butyric Acid
Common name for Pentanoic Acid (5C)
Valeric Acid
What odour does Propanoic Acid have?
Sweaty
What odour does Butanoic Acid have?
Human vomit
What are Long Chain Fatty Acids (LCFA)?
Either saturated or unsaturated even number of C >5
What is the effect of increased tail length on saturated FA melting point?
Mpt increases as tail length increases - more hydrophobic interactions so pack closer together = more E to overcome interactions
Common name for Hexadecanoic Acid (16C)
Palmitic Acid
Common name for Octadecanoic Acid (18C)
Stearic Acid
What is the effect of more C=C on the melting point of unsaturated FA?
More C=C decreases the mpt. Less tightly packed as fewer hydrophobic interactions so less E to overcome.
Position and number of C=C in Octadecenoic Acid
18C. 1 C=C, position 9 (18:1)
Position and number of C=C in Octadecadienoic Acid
18C. 2 C=C, positions 9, 12 (18:2)
Position and number of C=C in Octadecatrinoic Acid
18C. 3 C=C, positions 9, 12, 15 (18:3)
Common name for Octadecenoic Acid (18:1)
Oleic Acid
Common name for Octadecadienoic Acid (18:2)
Linoleic Acid
Common name for Octadecatrienoic Acid (18:3)
alpha-linolenic Acid
Reactions of FA
- Condensation
(FA + alcohol –> ester + water) - Hydrolysis
(ester + water –> FA + alcohol)
What are acylglycerols/acylglycerides?
FA + glycerol (ester bond) –> acylglycerol + water (condensation reaction)
Function of triacylglycerols?
Energy store i.e. seeds or adipose tissue
Characteristics of energy stores?
- Compact
- Easy access
- High E/ low density
- Insoluble
- High E/ low volume
- Readily stored and released
- Separated from cell contents (e.g. dense lipid droplets)
Chemical reactions of TAG?
- Hydrolysis
- Saponification
TAG + NaOH/ KOH –> glycerol + FA salts (soap) - Iodination
saturated FA + I2 –> unsaturated FA - Hydrogenation
unsaturated FA + H2 –> saturated FA
What is the Saponification Value?
mg of KOH needed to saponify 1g of oil or fat
high value = lots of short chains (lower weight so more KOH/g)
low value = lots of long chains
i.e. chainlength
What is the Iodine Number?
g of iodine which will combine with 100g of oil or fat
high value = lots of C=C/ high proportion of unsaturated FA
low value = fewer C=C/ lower proportion of saturated FA
i.e. number of C=C
X groups of phospholipids/phosphoglycerols`
- Serine
- Ethanolamine
- Choline
Phospholipid nomenclature
phophatidyl-X
Structures formed by amphipathic phospholipids
- Monolayers (liquid-air interface)
- Micelles
- Bilayers (liquid-liquid interface)
Components of biological bilayer membranes
- Sterols i.e. cholesterol, stigmasterol
- Proteins
- Carbohydrates
Types of membrane proteins
- Integral - span membrane or partial immersion
- Peripheral
Types of membrane transport
- Diffusion
- Facilitated Diffusion - carrier or channel proteins
- Active transport - primary (ATP hydrolysis) or secondary (co-transport)
- Osmosis
What is tonicity?
Osmotic pressure which is only exerted by solutes which cannot pass membranes. These solutes cause water to move from lower to higher tonicity.
