Biochemistry and Spectrophotometery Flashcards
What are the “building blocks” for protein macromolecules?
Amino acids
What are the “building blocks” for polysaccharides?
20 or more monosacchariddes
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
- 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.
- Amino acids are a source of energy (10-15% metabolic energy)
- Many inborn errors of metabolism are due to absence
of enzymes in the metabolism of amino acids - Amino Acids are precursors to other important
biomolecules
BRIEFLY explain what is meant by each of the terms: Protein Primary Structure, Secondary Structure, Tertiary Structure, 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.
α-helix, β-sheet
List four of the major roles of Protein.
- transporting molecules
- structural support (e.g. collagen in tendons and ligaments)
- growth (directs growth and development, e.g. growth hormone)
- immune response to foreign matter (antibodies)
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.
- storage (insulation, fuel)
- structure (membranes)
- specific biological actions (cofactors for enzymes)
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 (glucose + fructose)
- Lactose ( glucose + galactose)
- Maltose ( glucose + glucose)
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
Discuss the statement “The diagnosis and management of Diabetes mellitus is only of concern to a very small portion of the health care industry”
- This statement is 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
- Side effects of diabetes has very severe effects
How is Diabetes mellitus diagnosed
- Glycosuria test is suggestive but not diagnostic
- Blood glucose when fasting and random test can diagnose diabetes mellitus (>7.0 mmol/L fasting = diabetic)
Spectrophotometers can be used to measure the absorbance of light of a particular wavelength by a certain material. BRIEFLY 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 pathlength
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
List four (4) of the major functions of carbohydrates in a cell.
- Energy source
- Cell recognition
- Cell to cell communication
- Antibiotics
