Carbohydrates, Lipids and Proteins (SR)

Question 1

What are Monomers?

Answer 1

Individual molecules that make up a polymer

Question 2

What are Polymers?

Answer 2

Long chains
Composed of multiple Monomers
Bonded together in Repeating Pattern

Question 3

When does a Condensation Reaction Occur?

Answer 3

Occurs when two molecules combine to form a more complex molecule with removal of water

Question 4

When does a Hydrolysis Reaction Occur?

Answer 4

When larger molecules are broken down into smaller ones with the addition of water

Question 5

What are Monosaccharides?

Answer 5

Simplest Carbohydrates

Consisting of only one Sugar molecule (Glucose, Fructose & Galactose)

Question 6

What is Glucose?

Answer 6

A Hexose sugar with 2 Isomers:
α-Glucose
β-Glucose

Question 7

What are Disaccharides?

Answer 7

Sugars that are composed of two Monosaccharides
Joined together in a condensation reaction
Forming a Glycosidic Bond

Question 8

What is an example of a polysaccharide and is the main energy store in plants?

Answer 8

Amylopectin (Starch)

Composed of α-Glucose

Question 9

What is an example of a polysaccharide used for energy store in animals?

Answer 9

Glycogen

Composed of α-Glucose

Question 10

What is an example of a polysaccharide that is used as a structural component?

Answer 10

Cellulose

Composed of long unbranched chains of β-Glucose

Question 11

What are the two types of Fatty Acids?

Answer 11

1) Saturated

2) Unsaturated

Question 12

What is the difference between a Saturated Fatty Acid and an Unsaturated Fatty Acid?

Answer 12

Saturated has no C=C double bonds, as many hydrogens as possible

Unsaturated has at least 1 C=C double bond, therefore contains less Hydrogen, C=C bond causes a kink so can’t be closely packed together, which means it is liquid at room temp

Question 13

What is a triglyceride molecule?

Answer 13

Formed by joining one molecule of Glycerol to 3 Fatty Acids
Done by 3 Condensation Reactions
Forming Ester Bonds

Question 14

How do Triglycerides have key roles in Respiration and Energy Storage?

Answer 14

Due to its Insolubility and High Carbon : Hydrogen Ratio

Question 15

What is the difference between a Phospholipid and a Triglyceride?

Answer 15

Triglyceride has 3 Fatty Acid Chains

Phospholipid has 2 Fatty Acid Chains and a Phosphate molecule

Question 16

How do the properties of Phospholipids make them great for cell-surface membranes?

Answer 16

Hydrophobic Tails (fatty acids & glycerol) - Non-polar and insoluble in water (inner layer)
Hydrophilic Head (Phosphate) - Polar and soluble in water
Overall forms Phospholipid Bilayer (outer layer)

Question 17

What are Amino Acids?

Answer 17

Monomer Units used to make Proteins

Question 18

How many naturally occurring Amino Acids are there?

Answer 18

20

Only difference is the R Group

Question 19

What are Dipeptides and how are they formed?

Answer 19

Two amino Acids
Joined together by Condensation Reaction
Forming Peptide Bond

Question 20

What is a Polypeptide?

Answer 20

Polymer made of many Amino Acids

Joined together by Peptide bonds

Question 21

What are the 4 Structural Layers (Structures) of Proteins?

Answer 21

1) Primary (1º)
2) Secondary (2º)
3) Tertiary
4) Quaternary

Question 22

What is the Primary Structure (1º)?

Answer 22

Specific Sequence of Amino Acids in a Polypeptide Chain

Peptide Bonds hold them together

Question 23

What is the Secondary Structure (2º)?

Answer 23

Curling or Folding of Polypeptide Chain
Into α-helices and β-pleated sheets due to formation of H-Bonds

Hydrogen Bonds (H-Bonds) hold it together

Question 24

What is the Tertiary Structure?

Answer 24

Overall Specific 3D Shape of a Protein, determined by interactions b/w R groups and properties of R groups

Hydrogen Bonds, Ionic Bonds and Disulphide Bridges hold them together

Question 25

What is the Quaternary Structure?

Answer 25

Specific 3D shape of a protein determined by the multiple polypeptide chains and/or prosthetic groups bonded together Hydrogen Bonds, Ionic Bonds and Disulphide Bridges hold them together

Question 26

How do you test for Reducing Sugars?

Answer 26

Benedict's Reagent Reducing Sugar Reduces Cu (II) to Cu (I) Changes from Blue to Brick Red/Orange ppt formed

Question 27

What is the test for Starch?

Answer 27

Iodine in Potassium Iodide solution | Sample changes from Brown-Orange to dark Blue/Black if Starch present

Question 28

How do you test for Non-Reducing Sugars?

Answer 28

Break down into Reducing sugars by heating w/diluted HCl or hydrolyse using Enzymes Neutralise solution using Sodium Hydrogencarbonate Continue with Benedict's Reagent Brick Red/Orange ppt formed if reducing sugar present

Question 29

How do you test for Proteins?

Answer 29

Biuret Test Add Sodium/Potassium Hydroxide to solution containing crushed up/dissolved proteins/food to make solution alkaline Shake Add Copper (II) Sulphate Solution Solution should go from Blue to Purple if Proteins present

Question 30

How do you test for Lipids?

Answer 30

Emulsion Test Add Ethanol to test solution and shake for approx 1 min so it dissolves Add Water to the solution Any lipid will show as a milky white emulsion, the more lipid there is, the more noticeable the emulsion is Test can be Improved by adding Sudan III to stain Lipids Red

Question 31

What are Enzymes?

Answer 31

Biological Catalysts That speed up Rate of Reaction Remains Unchanged and re-usable @ end of reaction

Question 32

How do enzymes work?

Answer 32

They lower the Activation Energy

Question 33

What was the old theory for Enzyme Action?

Answer 33

Lock and Key | Each substrate is a 'key' and only fits to specific 'lock' (enzyme)

Question 34

What is the alternative theory for Enzyme Action?

Answer 34

Induced Fit: Substrate Induces change in enzyme so that it fits Enzyme when it contacts, moulds around Substrate Conformational change so enzyme moulds to fit substrate

Question 35

What is the Specificity of Enzymes down to?

Answer 35

Due to Tertiary Structure of Active Site | Allowing Complementary binding to Substrates

Question 36

What types of Reactions do Enzymes Catalyse?

Answer 36

Both Intra- and Extracellular reactions | That determine structures and functions from cellular to whole organism levels

Question 37

What factors affect Enzyme Activity?

Answer 37

1) pH 2) Temperature 3) Enzyme Concentration 4) Substrate Concentration 5) Competitive & Non-Competitive Inhibitor Conc.

Question 38

What is Competitive Inhibition?

Answer 38

Inhibition of Enzyme that is Reversible Can be overcome by increasing amount of Substrate Irreversible bonding called an Inactivator Level of Inhibition depends on conc. of Substrates

Question 39

What is Non-Competitive Inhibition?

Answer 39

``` When Inhibitor Binds to Allosteric Site Alters Specific shape of Enzymes Tertiary Site (Active Site) Disrupts shape of active sites Substrate can no-longer bind to Enzyme IRREVERSIBLE ```