biochem

Question 1

What are the “building blocks” for protein macromolecules?

Answer 1

Amino Acids

Question 2

What are the “building blocks” for polysaccharides?

Answer 2

20 or more monosaccharides - sugar

Question 3

What are the “building blocks” for nucleic acids?

Answer 3

Nucleotides

Question 4

What are the “building blocks” for lipid aggregates?

Answer 4

Fatty Acids

Question 5

What macromolecule/s can be made up of branched chains?

Answer 5

Carbohydrates

Question 6

How many standard amino acids are there?

Answer 6

20

Question 7

What is the general structure of an amino acid (diagram is ok)

Answer 7

• alpha (α) carbon
• carboxyl group
• amino group
• ‘R’ group

Question 8

How do the standard amino acids differ from one another?

Answer 8

The R group makes each amino acid different

Question 9

Amino acids can be classified according to their R group. Why might it be useful to use this classification?

Answer 9

Each type of R group has similar chemical properties (negatively charged, positive, polar, non-polar etc)

Question 10

What is a peptide bond?

Answer 10

A bond between 2 or more amino acids that form a peptide

Question 11

Explain why amino acids are important

Answer 11

Protein plays a crucial role in almost all biological processes and amino acids are the building blocks of it. A large proportion of our cells, muscles and tissue is made up of amino acids, meaning they carry out many important bodily functions, such as giving cells their structure and storing energy (10-15% metabolic energy). Amino Acids are also precursors to other important biomolecules

Question 12

Explain what is meant by each of the terms:
Protein Primary Structure
Protein Secondary Structure
Protein Tertiary Structure
Protein Quaternary Structure

Answer 12

Primary structure: linear sequence of amino acids
Secondary structure: the backbone of the polypeptide chain folds into regular geometric structures (α-helix, β-sheet, turns)
Tertiary structure: final folded form of the protein (the native form)
Quaternary structure: association of two, or more, polypeptide tertiary structures

Question 13

List two examples of terms that describe different secondary structures that can be found in proteins

Answer 13

a-helix and b-sheet

Question 14

List four of the major roles of Protein

Answer 14

transport
storage
motion
structural support

Question 15

Lipids may not be considered true macromolecules because of their structure. Briefly explain.

Answer 15

Individual monomers (fatty acids) are not covalently bound to each other in a macromolecular structure

Question 16

Name three (3) major functions of lipids

Answer 16

1. structural components of cell membranes
2. energy storage
3. function as important signalling molecules

Question 17

List some examples of lipid aggregates.

Answer 17

micelles, liposomes, membranes, lipoproteins

Question 18

Give one example of an important Monosaccharide

Answer 18

• D-Glucose (most abundant in nature)
• D-Fructose (common monosaccharide in honey and fruit)
• D-Ribose (component of DNA and RNA)

Question 19

Give one example of an important Disaccharide

Answer 19

• Sucrose (refined white sugar)
• Lactose (milk sugar)
• Maltose (malt or brewing sugar)

Question 20

List four (4) of the major functions of carbohydrates in cells

Answer 20

• Providing energy and regulation of blood glucose.
• Sparing the use of proteins for energy.
• Breakdown of fatty acids and preventing ketosis.
• Biological recognition processes

Question 21

Can two sugar molecules have different configurations despite having the same molecular formula?

Answer 21

Yes, most of them have a D configuration and an L configuration

Question 22

Explain the term Diabetes Mellitus

Answer 22

State of chronic hyperglycaemia which may result from genetic or environmental factors often acting jointly.
Type 2 - Insulin resistance
Type 1 - absolute deficiency of insulin

Question 23

Discuss the statement “The diagnosis and management of Diabetes mellitus is only of concern to a very small portion of the health care industry”.

Answer 23

False.
The prevalence in Australia is increasing and almost 50% of people with diabetes are undiagnosed which is very concerning to the health care industry considering that side effects of diabetes can be severe.

Question 24

How is Diabetes mellitus diagnosed?

Answer 24

Diagnosed is on the basis of low plasma glucose (>7.0 mmol/L fasting)

Question 25

Spectrophotometers can be used to measure the absorbance of light of a particular wavelength by a certain material. Explain what is meant by the term absorbance

Answer 25

The interaction of the light with the matter

Question 26

What is Beer’s Law?

Answer 26

Absorbance is proportional to the concentrations of the reducing species in the material sample

Question 27

What is Lambert’s Law?

Answer 27

Absorbance of a material sample is directly proportional to its path length

Question 28

What is the combined Lambert-Beer Law?

Answer 28

Absorbance is related to both concentration and path length

Question 29

Is it more convenient to use Absorbance or Transmittance to determine the concentration of a substance?

Answer 29

Absorbance, there is a directly proportional relationship between absorbance and concentration

Question 30

Why is the selection of optimal analytical wavelength important for spectrophotometric measurement?

Answer 30

To ensure that the spectro can detect the small changes in what is being measured

Question 31

Why is the selection and use of an appropriate Blank important for spectrophotometric measurement?

Answer 31

It is like a negative control, and the blank used should not have the same effects as those that are expected to be measured by the spectro