2: Lipids Flashcards Preview

Biology: Y12 EOY > 2: Lipids > Flashcards

Flashcards in 2: Lipids Deck (24)
Loading flashcards...
1
Q

What are lipids?

A

carbon compounds made by living organisms that are mostly or entirely hydrophobic

2
Q

Name the 3 main types of lipid.

A
  • triglycerides
  • phospholipids
  • steroids
3
Q

Describe ‘triglycerides’. Give 2 general examples.

A
  • made from 3 fatty acids and 1 glycerol by condensation reactions so they have 3 hydrocarbon tales
  • fats and oils
4
Q

Describe ‘phospholipids’.

A
  • 2 fatty acid tails linked to glycerol, with a phosphate group instead of the third fatty acid
  • phospholipids are partly hydrophobic and form the basis of membranes
5
Q

Describe ‘steroids’. Give 4 examples of steroids.

A
  • all types of steroids have similar structure
  • 4 fused rings in their molecule
  • cholesterol, progesterone, estrogen, testosterone
6
Q

How can molecules be identified as lipids?

A
  • if they have 2 or 3 hydrocarbon chains

- if they have the quadruple ring structure (steroids)

7
Q

Draw a molecular structure of a glycerol molecule. (p22)

A

-

8
Q

How are hydrocarbon chains often shown in molecular diagrams?

A

as a zigzag line (see p22)

9
Q

How are rings of carbon atoms often shown in molecular diagrams?

A

hexagons or pentagons (see p22)

10
Q

Draw the molecular structure of a triglyceride. (p22)

A

-

11
Q

Draw the molecular structure of a phospholipid. (p22)

A

-

12
Q

Draw the molecular structure of a testosterone (p22).

A

-

13
Q

How many parts to a fatty acid are there? What are they?

A
  • two parts

- carboxyl group (acid) and an unbranched hydrocarbon chain (fatty)

14
Q

Draw a molecular diagram of a carboxyl group. Draw a molecular diagram of a hydrocarbon chain. (p22)

A

-

15
Q

What is the fast way of showing the molecular structure of a hydrocarbon chain?

A
  • CH2 - (CH2)n - CH3
16
Q

What two factors vary in a chain of hydrocarbons?

A
  • the number of carbon atoms in the hydrocarbon chain

- the bonding of the carbon atoms to each other and to hydrogens

17
Q

What does ‘saturated’ mean when talking about fatty acids?

A

all carbon atoms in the chain are connected by single covalent bonds = the number of hydrogen atoms bonded to the carbons cannot be increased

18
Q

What does ‘unsaturated’ mean when talking about fatty acids?

A

contain one or more double bonds between carbon atoms in the hydrocarbon chain = more hydrogen could be bonded to the carbons if a double bond was replaced by a single bond

19
Q

Draw an unsaturated fatty acid. (p22)

A

-

20
Q

What does ‘monounsaturated’ mean when talking about fatty acids?

A

only one double bond (between carbon atoms in hydrocarbon chain)

21
Q

What does ‘polyunsaturated’ mean when talking about fatty acids?

A

two or more double bonds (between carbon atoms in hydrocarbon chain)

22
Q

What does the position of the nearest double bond to the the CH3 terminal determine?

A
  • third bond from terminal = omega-3 fatty acid

- sixth bond from terminal = omega-6 fatty acid

23
Q

What does ‘cis unsaturated’ mean when talking about fatty acids?

A

hydrogen atoms are bonded to carbon atoms on the same side of a double bond

24
Q

What does ‘trans unsaturated’ mean when talking about fatty acids?

A

hydrogen atoms are bonded to carbon atoms on opposite sides of a double bond