Biological Molecules

Question 1

Name the components of Carbohydrates and the two types

Answer 1

Carbon, hydrogen, oxygen

Simple sugars, complex carbohydrates

Question 2

What is a simple sugar?

Answer 2

Soluble in water, sweet, simple units of sugar or 2 molecules a joined (disaccharides), supply energy for respiration (glucose + oxygen = CO2 + H2O

Question 3

What is a complex carbohydrate?

Answer 3

Made of thousands of glucose molecules, storage molecules (starch in plants, glycogen in animals), insoluable, compact to store large amounts, less reactive, cellulose is another cc

Question 4

What is protein composed of?

Answer 4

Carbon, hydrogen, oxygen, nitrogen

Question 5

What are proteins made up of?

Answer 5

20 different amino acids, joined together in different combinations

Question 6

What is the function of the protein?

Answer 6

Structural molecules, controlling chemical reactions, messenger molecules, combating disease, transport

Question 7

What are lipids composed of and what are the types?

Answer 7

Carbon, hydrogen, oxygen and are made of glycerol, fatty acids
Saturated fatty acids = FATS, solid at room temperature
Unsaturated acids = OILS, liquid at room temperature

Question 8

What is the test for glucose?

Answer 8

Benedicts test
5cm cubed of benedicts solution
Heat using a water bath at 60 degrees
Will changed from blue to brick red

Question 9

What is the test for starch?

Answer 9

Iodine
2-5 drops of iodine solution
Brown - blue/black

Question 10

What is the test for proteins?

Answer 10

Biuret reagent
2-5 drops biuret reagent
Pale blue - purple

Question 11

What is the test for lipids?

Answer 11

Emulsion
2cm cubed of ethanol
Add solution to boiling tube of water
White emulsion will form

Question 12

What are enzymes?

Answer 12

Biological catalysts that control chemical reactions.

Nucleus contain genes which control the production of enzymes, which catalyse the reactions in the cytoplasm

Question 13

Describe enzyme controlled reactions

Answer 13

Maltose —(maltase)— glucose
The substance the enzyme acts on in the substrate(maltose), the substance produced by the reaction is the product(glucose), and the enzymes (maltase), which usually are the same as the substrate but with -are

Question 14

What is a catabollic and anabolic reaction?

Answer 14

Catabollic is breaking down large molecules to smaller products e.g digestion
Anabolic is building large molecules from smaller substrates e.g DNA

Question 15

How do enzymes work?

Answer 15

Lock and key theory
Substrate binds to active site but the active site of a particular enzyme has a specific shape which complimentary to the shape of the substrate. Once the reaction has occurred the products do not fit as well so released, after the reaction the enzyme molecule is free to catalyse the next.
Binding to the active site enable the reaction to occur w lower activation energy

Question 16

How does temperature effect enzymes?

Answer 16

As temp increases there is more kinetic energy (collision theory), a rise in 10 degrees means twice as fast but at high temps it is irreversibly changed because the thermal energy alters the bonds holding the protein in the specific shape and has been denatured
The optimum temp is 37 degrees

Question 17

What is the effect of ph?

Answer 17

The shape is dependant on ph, and each has its own ph and chemical bonds that hold the correct shape at that ph. A change will disrupt the chemical bonds and change the shape so it is no longer complimentary to the active site

Question 18

Effect of SA?

Answer 18

Reactions happen faster is the substrate has a larger SA because there are more substrate accessible to the enzyme

Question 19

Effect of conc?

Answer 19

Occur faster is the conc is increased as there are more enzyme and substrate molecules