biochem Flashcards
What are the “building blocks” for protein macromolecules?
Amino Acids
What are the “building blocks” for polysaccharides?
20 or more monosaccharides - sugar
What are the “building blocks” for nucleic acids?
Nucleotides
What are the “building blocks” for lipid aggregates?
Fatty Acids
What macromolecule/s can be made up of branched chains?
Carbohydrates
How many standard amino acids are there?
20
What is the general structure of an amino acid (diagram is ok)
- alpha (α) carbon
- carboxyl group
- amino group
- ‘R’ group
How do the standard amino acids differ from one another?
The R group makes each amino acid different
Amino acids can be classified according to their R group. Why might it be useful to use this classification?
Each type of R group has similar chemical properties (negatively charged, positive, polar, non-polar etc)
What is a peptide bond?
A bond between 2 or more amino acids that form a peptide
Explain why amino acids are important
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
Explain what is meant by each of the terms: Protein Primary Structure Protein Secondary Structure Protein Tertiary Structure Protein Quaternary Structure
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
List two examples of terms that describe different secondary structures that can be found in proteins
a-helix and b-sheet
List four of the major roles of Protein
transport
storage
motion
structural support
Lipids may not be considered true macromolecules because of their structure. Briefly explain.
Individual monomers (fatty acids) are not covalently bound to each other in a macromolecular structure
Name three (3) major functions of lipids
- structural components of cell membranes
- energy storage
- function as important signalling molecules
List some examples of lipid aggregates.
micelles, liposomes, membranes, lipoproteins
Give one example of an important Monosaccharide
- D-Glucose (most abundant in nature)
- D-Fructose (common monosaccharide in honey and fruit)
- D-Ribose (component of DNA and RNA)
Give one example of an important Disaccharide
- Sucrose (refined white sugar)
- Lactose (milk sugar)
- Maltose (malt or brewing sugar)
List four (4) of the major functions of carbohydrates in cells
- Providing energy and regulation of blood glucose.
- Sparing the use of proteins for energy.
- Breakdown of fatty acids and preventing ketosis.
- Biological recognition processes
Can two sugar molecules have different configurations despite having the same molecular formula?
Yes, most of them have a D configuration and an L configuration
Explain the term Diabetes Mellitus
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
Discuss the statement “The diagnosis and management of Diabetes mellitus is only of concern to a very small portion of the health care industry”.
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.
How is Diabetes mellitus diagnosed?
Diagnosed is on the basis of low plasma glucose (>7.0 mmol/L fasting)
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
The interaction of the light with the matter
What is Beer’s Law?
Absorbance is proportional to the concentrations of the reducing species in the material sample
What is Lambert’s Law?
Absorbance of a material sample is directly proportional to its path length
What is the combined Lambert-Beer Law?
Absorbance is related to both concentration and path length
Is it more convenient to use Absorbance or Transmittance to determine the concentration of a substance?
Absorbance, there is a directly proportional relationship between absorbance and concentration
Why is the selection of optimal analytical wavelength important for spectrophotometric measurement?
To ensure that the spectro can detect the small changes in what is being measured
Why is the selection and use of an appropriate Blank important for spectrophotometric measurement?
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
