lipids

Question 1

name two groups of lipids

Answer 1

fats and oils

Question 2

physical difference between fats and oils

Answer 2

fats are solids at room temp and oils are liquids

Question 3

what chemicals do all lipids contain

Answer 3

carbon
oxygen
hydrogen

Question 4

what do lipids contain less of compared to carbs

Answer 4

oxygen

Question 5

what two organic chemicals are fats and oils made of

Answer 5

fatty acids and glycerol

Question 6

what are fatty acids and glycerol combined with

Answer 6

ester bonds

Question 7

glycerol chemical formula

Answer 7

C3H8O3

Question 8

chemical structure of all fatty acids

Answer 8

long hydrocarbon chain
a pleated backbone of carbon atoms with hydrogen atoms
and a carboxyl group

Question 9

in what ways do fatty acids differ

Answer 9

length of the carbon chain can differ
-fatty acid many be saturated or unsaturated

Question 10

structure of saturated fatty acids

Answer 10

each carbon atom is joined to the next one to it by a single covalent bond
eg stearic acid

Question 11

structure of unsaturated fatty acids

Answer 11

the carbon chains have one or more double covalent bond in them

Question 12

monosaturated fatty acid

Answer 12

one double bond

Question 13

polyunsaturated fatty acid

Answer 13

one or more double bond
eg linoleic acid

Question 14

why is linoelic acid important in diets

Answer 14

because we cant make it from other chemicals

Question 15

what is a fat or oil a result of

Answer 15

when glycerol combined with one two or three fatty acids to make monoglyceride diglyceride or triglyceride

Question 16

what happens when glycerol bonds with a fatty acid

Answer 16

a bond is formed in a condensation reaction between the carboxyl group of a fatty acid and one of the hydroxyl group

Question 17

how does this result in a ester bond

Answer 17

a molecule of water is removed and an ester bond is made

Question 18

what is an ester bond condensation reaction called

Answer 18

esterification

Question 19

how many atoms of oxygen are there in a triglyceride molecule

Answer 19

6 atoms

Question 20

what happens when lipids are oxidised in respiration

Answer 20

bonds are broken are carbon dioxide and water are the last products.
-this reaction can be used to derive lots of ATP

Question 21

why are lipids usefull

Answer 21

because they store 3 times the amount of energy as carbs do

Question 22

why is lipids being hydrophobic important

Answer 22

key for waterproofing organisms

Question 23

use of oils in waterproofing

Answer 23

they are hydrophobic so protect organisms outer surface area

Question 24

why are lipids good insulators

Answer 24

a fatty sheath insulates your nerves so electrical impulses go faster called myelin

Question 25

why do lipids have a low density and its importance

Answer 25

body fat of mammals make them float easily -

Question 26

lipids being insoluble in water only

Answer 26

means they dont interfere with osmotic potential and water bases reactions

Question 27

what ions are present in the cytoplasm of every cell

Answer 27

inorganic phosphate ions PO43-

Question 28

how are phospholipids formed

Answer 28

one of the hydroxyl groups of glycerol undergoes esterification with a phosphate group instead with a fatty acid and forms said thing

Question 29

property of fatty chains of phospholipids

Answer 29

the fatty acid chains are neutral and insoluble

Question 30

property of the phosphate group

Answer 30

it has a slight negative charge and is soluble in water so both parts of the molecule behave very differently

Question 31

what part of the PL is hydrophillic

Answer 31

the polar phosphate group

Question 32

what happens of molecules are tightly packed together

Answer 32

they form a monolayer of tightly packed atoms

Question 33

micelles

Answer 33

spherical aggregate of molecules in water with hydrophobic areas in the middle and hydrophillic areas outside

Question 34

bi layer

Answer 34

a double layer of closely packed atoms or molecules

Question 35

unit membrane

Answer 35

a bilayer structure formed by phospholipids in an aqueous enviornment with the hydrophobic tails in the middle and hydrophillic heads on the outside

Question 36

contrast unsaturated and saturated fatty acids

Answer 36

saturated= -only single bonds -straight chain molecules have many contact points -higher melting point -found in animals fats unsaturated= -double carbon bonds -kinked molecules fewer contact points -lower melting point -found in plant oils

Question 37

structure of tryglycerdes to their function

Answer 37

high energy mass ratio= high calorific value from oxidation insoluble chain= protection and waterproofing -slow conductor of heat=insulation less dense than water=buoyancy of aquatic animals

Question 38

describe function and structure of phospholipids

Answer 38

amphipathic=glycerol backbone attached to 2 hydrophobic fatty acid tails and hydrophillic phosphate group head forms bilayer= component of membranes tails can spray outwards=waterproofing

Question 39

bond only between carbs

Answer 39

hydrogen bonds

Question 40

bonds only between lipids

Answer 40

ester bonds

Question 41

bonds between lipids and carbs

Answer 41

covalent bonds