LEC 7 LIPIDS AND PROTEINS

Question 1

What are lipids?

Answer 1

Fats and oils containing only&raquo_space; Carbon, Hydrogen & Oxygen

Question 2

Why are lipids more hydrophobic than carbohydrates?

Answer 2

Lipids have less oxygen than < carbohydrates

-More hydrophobic than CHO
-More lipid soluble < dissolve in oil

Question 3

What are the functions of lipids?

Answer 3

• Stores energy
• Helps w/ movement of particles
• Absorb vitamins
• Make hormones

Question 4

Name the 4 types of lipids?

Answer 4

1. Fatty acids
2. Triglycerides
3. Phospholipids
4. Steroids

Question 5

What are Fatty acids?

Answer 5

The monomers of lipids (simple component)

Question 6

A fatty acid consist of a ________ functional group attached to a _____

Answer 6

_Carboxylic Acid
_Hydrocarbon chain

NOTE:
Hydrocarbon chain may be ‘VERY LONG’ and include ‘DOUBLE BONDS’

Question 7

Name the three (3) classes of fatty acids

Answer 7

1. Saturated
2. Monunsaturated
3. Polyunsaturated

Question 8

Define Saturated Fatty Acids?

Answer 8

No double bonds - Mostly in animal fats

Note:
Each carbon is ‘saturated’ with hydrogen atoms.

Question 9

Give an example of saturated fatty acid

Answer 9

Palmitic acid (C16 H32 O2)

Question 10

Define Monounsaturated fatty acids?

Answer 10

Has ONE DOUBLE BONDS between carbon
(found in plant oil)

Question 11

Give an example of monounsaturated fatty acids?

Answer 11

Oleic acid (C18 H34 O2)

(found in olive oil)

Question 12

Define Polyunsaturated fatty acids?

Answer 12

Has TWO(2) or more DOUBLE BONDS between carbon

Question 13

What’s an example of Polyunsaturated fatty acids?

Answer 13

Linoleic acid (C18 H32 O2)

(Found in seeds)

Question 14

What are Triglycerides fatty acids?

Answer 14

Stored fatty acid (unused fat stored)

formed by linking three with glycerol (3 carbon sugar)

Question 15

1. How is fatty acids attach to glycerol to form triglycerides?
2. How many molecules of water is formed from each triglycerides?

Answer 15

1. Dehydration synthesis reaction
2. Three (3) molecules of water is formed from each

Question 16

What are the functions of Triglycerides?

Answer 16

Stored in ‘fat cells’ for:
-Insulation
-Temperature
-Energy

Question 17

GOOD AND BAD FATTY ACIDS
(SOURCE/USE)

Answer 17

• Omega3 fats >essential>polyunsaturated fatty acid>in flaxseed oil&fish>cardiovascular health
• Saturated fats>increase risk of heart disease

-Trans fats>increase risk of heart disease

Question 18

What are Phospholipids?

Answer 18

Major component of cell membrane (75%)

Question 19

What is the structural formula of phospholipids?

Answer 19

Made of:
Glycerol, 2 fatty acids, phosphate group attach to nitrogen-containing group

Question 20

Whaty are phospholipids considered to be “amphipathic”?

Answer 20

Hydrophilic - head
Hydrophobic - Tail

(Amphipathic = BOTH polar & nonpolar)

Question 21

What are steroids?

Answer 21

Form by containing 4 rings from cholesterol (which form bile and hormones)

Question 22

T/F
The 4 hydrocarbon rings of steriods are non-polar?

Answer 22

TRUE

(Hydrophobic - water hating)

Question 23

What are the functions of steriods?

Answer 23

• Cell communication (through blood stream)

Question 24

Name examples of steriods?

Answer 24

• Testosterone
• Estrogen
• Aldosterone
• Cortisol

Question 25

What are proteins?

Answer 25

Large molecules made of amino acids

Note/Facts:
- Type of fatty acid
- 20% of body mass
- Multiple functions

Question 26

T/F
Proteins are made of 20 different amino acids?

Answer 26

TRUE

Question 27

What is the amino acid structure/properties of proteins?
(20 amino acids)

Answer 27

Each: Central carbon atom > amino group > carboxylic acid group

Question 28

Each amino acid has a unique what______?

Answer 28

R group

Note:
- R group varies based on complex properties
- R group determines amin acid properties

Question 29

Name examples of amino acids?

Answer 29

-Hydrogen
-Tryptophan (complicated)
-Cysteine

Question 30

What are Peptides and Peptides bonds?
(How they are formed)

Answer 30

Amino acid linked by dehydration snythesis
(peptide + peptide = peptide bond)

Question 31

What is the structure/properties of peptide bond?
(Operation of how the bond is formed)

Really not as complicated as it seems :)

Answer 31

Amino group + Carboxylic acid group - lose water molecule

Dehydration Synthesis: How bond is form
Amino group > lose one hydrogen (-H)
Carboxylic group > lose one hydroxyl (-OH)
(H2O -lost of water)

Alternative Explanation:
(-H & -OH = Lost of water molecule = Dehydration synthesis) = Formation of peptide bond
(C-N bond > end result) (carbon-Nitrogen)

Question 32

What is a depeptide?

Answer 32

Compose of two (2) amino acids
(Through hydrolysis > water molecule (H2O) is used to break down peptide bond = Dipeptide)

Result in the reverse of peptide bond. (+H & +OH = Add water)

Note:
Is held together by a peptide bond

Question 33

whats the difference between ‘Peptide bond’ and ‘Dipeptide’?

(Personal note - needed to understand)

Answer 33

Dehydration synthesis & Hydrolysis

Peptide bond = Dehydration snythesis>Lost of water molecule (-H -OH = -H2O) (C+N<end result)
Dipeptide = Hydrolysis>Add water molecule (+H +HO = H2O)

Question 34

What is a ‘tripeptide’ bond

Answer 34

Two peptide bonds

Question 35

what is a polypeptide?

Answer 35

Poly = Multiple/Many
Contains 10 or more amino acids

Question 36

What are ‘Fibrous protein’?

Where are the located?

Answer 36

Long strands

Found in: hair, nails, tendons & bone

Question 37

What are ‘Globular proteins’?

Where are they found?

Answer 37

Spherical shape

Found in:Enzymes, hormones & cell messengers

Question 38

What are the 4 levels of protein structure?

Answer 38

1. Primary
2. secondary
3. Tertiary
4. Quaternary

Question 39

What is Protein Denaturation?

Answer 39

Protein lose shape > Due to heat, pH & chemicals

Note:
-When protien cant function we become sick
-Having a fever/high temp throws off protein function
-pH becomes off < Due to infection/illness