3 biological molecules

Question 1

-
-

Answer 1

-carbohydrates
-fats/lipids
-proteins

Question 2

Types of carbohydrates:
1.
2.
3.
(all has three elements: …)

Answer 2

1. monosaccharide
2. disaccharide
3. polysaccharide
   (Carbon, Hydrogen, Oxygen)

Question 3

Functions of carbohydrates I:
1. releases _______ for cellular activities (_______ source of _______)
2. form _________ structures (e.g. ____ ____ in plant cells)

Answer 3

1. energy, primary, energy
2. supporting, cell walls

Question 4

Functions of carbohydrates II:
3. formation of ________ acids (e.g. ___)
4. form ________ found between joints or ______ in trachea

Answer 4

3. nucleic, DNA
4. lubricants, mucus

Question 5

Examples of monosaccharides +chemical formula:
1.
2.
3.
(all has formula of …)

Answer 5

1. glucose
2. fructose
3. galactose
   (C6H12O6)

Question 6

Characteristics of monosaccharides:
-can pass through ____ _________
-cannot be ______ into ________ _________

Answer 6

-cell membrane
-digested, simpler molecules

Question 7

Examples of disaccharides + components:
1.
2.
3.
(all has formula of …)

Answer 7

1. maltose (glucose +glucose)
2. lactose (glucose +galactose)
3. sucrose (glucose +fructose)
   (C12H22O11)

Question 8

Disaccharides can be broken down by _________. (e.g. ____ +_________=>glucose +glucose)

Answer 8

hydrolysis (e.g. H20 +maltose=>glucose +glucose)

Question 9

Disaccharides are formed through __________ _______. (e.g. glucose +glucose=>________+____)

Answer 9

condensation reaction, (e.g. glucose +glucose=>maltose +H2O)

Question 10

Examples of polysaccharides + found in animal/plant cell:
1.
2.
3.
(all made up of …)

Answer 10

1. starch (animal)
2. glycogen (animal)
3. cellulose (plant)
   (…glucose molecules)

Question 11

-Role of starch is as a _________ in ______ (found in…)
-Role of glycogen is as a ________ in _________(found in…)

Answer 11

-storage, plants (storage organs like tubers)
-storage, animals (liver and muscles of mammals)

Question 12

-Role of cellulose is as _________ of ______ _____(found in…) <also></also>

Answer 12

-protection, plant cells (cell walls of plant cells) <dietary></dietary>

Question 13

-

Answer 13

-Benedict’s test for reducing sugars’ presence
-iodine test for starch presence

Question 14

All reducing sugars
1.
2.
3.
4.
5.

Answer 14

1. Glucose
2. Fructose
3. Galactose
4. Maltose
5. Lactose
   (X sucrose X)

Question 15

Steps for Benedict’s test:
1. add ______ ___ of Benedict’s solution to sample food solution
2. ______ thoroughly
3. immerse in _________ ______ ____ for 2-3mins

Answer 15

1. equal vol.
2. shake
3. boiling water bath

Question 16

Results for Benedict’s test & meaning:
-brick red precipitate (indicating…)
-blue to yellow/orange ppt. (indicating…)
-blue to green (indicating…)
-remains blue (indicating…)

Answer 16

-large amt of r.s.
-moderate amts. of r.s.
-traces of r.s.
-no r.s.

Question 17

Why glycogen and starch are suitable storage materials:
-they are ________ in ______ (hence wont change ___ in ____)
-they have ________ shapes, take up _______ space. (more _______ per unit volume)

Answer 17

-insoluble, water, w.p., cells
-compact, lesser, glucose

Question 18

Why glycogen and starch are suitable storage materials:
-they are too _____ to diffuse across ____ ________
-can easily be _______ _____ (h_________) to _____ when needed

Answer 18

-large, cell membrane
-broken down, hydrolysed, glucose