Biochemistry 0100

Question 1

What is the molecular structure of the water molecule?

Answer 1

The water molecule is made up of two hydrogen atoms covalently bonded to one oxygen atom.

Question 2

Describe water’s dipole nature

Answer 2

The water molecule has an unequal distribution of charge which is described as a dipole. The dipole is caused because of the bonding, the water molecule has a covalent bond and due to that the oxygen atom has a slightly more negative charge(delta -) because of the electron sharing. Oppositely for the hydrogen atoms it gains a more positive charge(delta +). Even though water has a neutral charge it still has areas that have either positive and negative charge.

Question 3

Describe water’s polarity and hydrogen bonding

Answer 3

The hydrogen bonding occurs when water molecules are attracted to eachother, the positive charge of hydrogen atoms attract the negatively charged oxygen atoms in other molecules.

Question 4

Properties of water and its role in the environment.

Answer 4

Water is needed within and around living organisms. Cells are made up of 70% to 90% water and this water is needed for survival. Water is the habitat of many living organisms and life evolved from water. The structure of the water molecule allows it to be a solvent thus enabling medabolic reactions to occur.

Question 5

Structure of aldose and ketose

Answer 5

H- C = O
l
H -C - OH
l
H- C - OH
l
H
Aldose

 H
  l H- C - OH
  l
 C = O
  l H- C - OH
  l
 H Ketose

Question 6

Give a summary of differences between monosaccharides, disaccharides and polysaccharides.

Answer 6

The differences between monosaccharides, disaccharides and polysaccharides are that monosaccharides are singular units while disaccharides are a combination pf two monosaccharide units and a polysaccharide is a combination of three or more monosaccharide units.

Question 7

What are the physical and chemical properties of monosaccharides, disaccharides and polysaccharides?

Answer 7

The physical properties of monosaccharides and disaccharides are they are small molecules, have a sweet taste, is readily soluble in water, crystalline and name always ends in ‘ose’. The physical properties of polysaccharides are they are macromolecules, not sweet to taste, is insoluble or partially soluble in water and is non-crystalline.

The chemical properties of monosaccharides are that they are all reducing sugars. The chemical properties of disaccharides are that some are reducing and some are non-reducing sugars. The chemical properties of polysaccharides are that they are all non-reducing sugars.

Question 8

What is the general formula of a monosaccharide, disaccharide and polysaccharide?

Answer 8

The general formula of a monosaccharide is (CH2O)n, the general formula of a disaccharide is C12H22O11 and the general formula of a polysaccharide is Cx(H2O)y .

Question 9

What are the examples and functions of monosaccharides, disaccharides and polysaccharides?

Answer 9

Some examples of monosaccharides are trioses, pentoses and hexoses. The function of trioses are to intermediate respiration, photosynthesis and other branches of carbohydrate metabolism. The function of pentoses are the synthesis of nucleic acids, coenzymes and ATP. The function of hexoses are to supply energy, synthesize disaccharides and polysaccharides.

Some examples of disaccharides are sucrose, maltose and lactose. The functions of disaccharides are to supply energy to the human body.

Some examples of polysaccharides are starch, glycogen, cellulose, heparin and peptidoglycan. Functions of polysaccharides are to provide structural support to cells, act as an energy store and sending cell signals as communication.