Questão 1
Questão
What are the “building blocks” for protein macromolecules?
Responda
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Amino acids
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Polysaccharides
Questão 2
Questão
What are the “building blocks” for polysaccharides?
Questão 3
Questão
What are the “building blocks” for nucleic acids?
Questão 4
Questão
A nucleotide consists of three things:
- A nitrogenous base, which can be either adenine, guanine, cytosine, or thymine (in the case of RNA, thymine is replaced by uracil).
- A five-carbon sugar, called deoxyribose because it is lacking an oxygen group on one of its carbons.
- One or more phosphate groups.
Questão 5
Questão
What are the “building blocks” for lipid aggregates?
Responda
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Fatty acids and glycerol
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Fatty acids and omega 3
Questão 6
Questão
What macromolecule/s can be made up of branched chains?
Responda
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Polysaccharides
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Monosaccharides
Questão 7
Questão
How many standard amino acids are there?
Questão 8
Questão
How do the standard amino acids differ from one another?
Questão 9
Questão
Amino acids can be classified according to their R group. Why might it be useful to use this classification? (Hint, might some amino acids with similar R groups have similar properties?)
Questão 10
Questão
What does it mean if something is Chiral?
Responda
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The property of having a 'left' and 'right' form of a molecule/compound. They cannot be superimposed on each other as they are not 'identical'
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The property of having completely identical forms of a molecule/compound. They can be superimposed on each other as they are 'identical'
Questão 11
Questão
Enantiomers are chiral molecules that are mirror images of one another. Furthermore, the molecules are non-superimposable on one another. This means that the molecules cannot be placed on top of one another and give the same molecule. Chiral molecules with one or more stereocenters can be enantiomers.
Questão 12
Questão
What does the L and D in amino acids stand for?
Responda
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The L in front of an amino acid is a shortened scientific notation for “levorotatory', the D means 'dextrorotatory'. The terms dextrorotatory and levorotatory refer to an optical property that can be observed and measured in a laboratory, by shining a beam of polarized light through a medium containing the substance.
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The L in front of an amino acid is a shortened scientific notation for “levorous', the D means 'dextrous'. The terms dextrous and levorous refer to an optical property that can be observed and measured in a laboratory, by shining a beam of polarized light through a medium containing the substance.
Questão 13
Questão
Levorotatory is (of a compound) having the property of rotating the plane of a polarized light ray to the left, i.e. anticlockwise facing the oncoming radiation.
Questão 14
Questão
Levorotatory is (of a compound) having the property of rotating the plane of a polarized light ray to the right, i.e. anticlockwise facing the oncoming radiation.
Questão 15
Questão
Dextrorotatory (of a compound) is having the property of rotating the plane of a polarized light ray to the right, i.e. clockwise facing the oncoming radiation.
Questão 16
Questão
What is a peptide bond?
Questão 17
Questão
Explain why amino acids are important.
Responda
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Amino acids are a source of energy, they contribute about 10-15% of metabolic energy and are precursors to other important biomolecules
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Although Amino acids are not a source of energy, they contribute about 5-10% of cattabolic energy and occasionally are precursors to other important biomolecules
Questão 18
Questão
Select Three examples of important Disaccharides.
Responda
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Sucrose
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Lactose
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Maltose
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Fructose
Questão 19
Questão
How is Diabetes mellitus diagnosed?
Responda
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Blood glucose test
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Glycosuria test
Questão 20
Questão
Select the Four major roles of Protein.
Responda
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Plays a role in immunity, growth, regulation of genes and communication (hormones, cells)
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Generates movement in cells and tissues (e.g. myosin in muscle) and structural support
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Breaks down covalent bonds and transforms one chemical into another (e.g. enzymes)
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Carries and stores small molecules or ions (e.g. haemoglobin carrying oxygen)
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Prevents urine incontinence, hair growth and eye function
Questão 21
Questão
Give an example of important Monosaccharides
Responda
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D-Glucose, D-Fructose, D-Ribose
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D-Glucose, D-Fructose, D-Lactose
Questão 22
Questão
Select three (3) major functions of lipids.
Responda
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Storage - fuels, insulation, protection, heat production
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Structural - biological membranes
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Specific biological actions - Biological messengers - intracellular and extracellular, Co-factors for enzymes, Electron carriers and effectors
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Storage - ATP, Warmth, Oxytocin
Questão 23
Questão
Select Four examples of lipid aggregates.
Responda
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micelles
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liposomes
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membranes
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lipoproteins
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lysosomes
Questão 24
Questão
Select four (4) of the major functions of carbohydrates in a cell
Questão 25
Questão
What is Beer ’s Law?
Questão 26
Questão
What is Lambert’s Law?
Questão 27
Questão
What is the combined Lambert-Beer Law?
Responda
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As the light passes through a solution, the intensity of light transmitted decrease, exponentially with increasing path length (lamberts law) and with increasing concentration of the absorbing substance (Beers law)
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As the light passes through a solution, the intensity of light transmitted decrease, exponentially with increasing path length (lamberts law) and with decreasing concentration of the absorbing substance (Beers law)
Questão 28
Questão
Lipids may not be considered true macromolecules because of their structure. Briefly explain.
Responda
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Because individual monomers (fatty acids) are not covalently bound to each other in a macromolecular structure
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individual monomers (fatty acids) are not ionic compounds to each other in a macromolecular structure
Questão 29
Questão
Can two sugar molecules have different configurations despite having the same molecular formula?
Questão 30
Questão
Is it more convenient to use Absorbance or Transmittance to determine the concentration of a substance?
Responda
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Transmittance - The difference between the intensity of the incident light beam Io and the intensity of the light transmitted by the solution It
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Absorbance - The difference between the intensity of the incident light beam Io and the intensity of the light transmitted by the solution It
Questão 31
Questão
What is the general structure of an amino acid
Responda
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alpha (α) carbon, carboxyl group, amino group, ‘R’ group
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alpha (α) hydrogen, carboxyl group, amino group, ‘R’ group
Questão 32
Questão
Explain the term Diabetes mellitus
Questão 33
Questão
Spectrophotometers can be used to measure the absorbance of light of a particular wavelength by a certain material. What is meant by the term absorbance?
Questão 34
Questão
Why is the selection of optimal analytical wavelength important for spectrophotometric measurement?
Responda
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Because different compounds absorb light at different wavelengths, a spectrophotometer can be used to distinguish compounds by analyzing the pattern of wavelengths absorbed by a given sample.
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Because some compounds do not absorb light at different wavelengths, therefore a spectrophotometer can not be used to distinguish compounds by analyzing the pattern of wavelengths absorbed by a given sample.
Questão 35
Questão
List two examples of terms that describe different secondary structures that can be found in proteins.
Questão 36
Questão
What is meant by the term 'Protein Primary Structure'
Questão 37
Questão
What is meant by the term 'Protein Secondary Structure'
Responda
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Secondary protein structure is the general 3-dimensional form of local segments of a protein. The most common secondary structures are alpha helices and beta-pleated sheets.
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This process happens in the nucleus. In the cytoplasm, ribosomes will interact with the transcript and create a protein (polypeptide) from individual amino acids.
Questão 38
Questão
What is meant by the term 'Protein Tertiary Structure'
Responda
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The general 3-dimensional form of local segments of a protein. The most common structures are alpha helices and beta-pleated sheets.
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Tertiary structures involve packaging and folding the secondary structures into compact globular regions called protein domains.
Questão 39
Questão
What is meant by the term 'Protein Quaternary Structure'
Responda
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Protein quaternary structure is the number and arrangement of multiple folded protein subunits in a multi-subunit complex.
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Amino acids form structures such as alpha helices, beta sheets, and random coils, which in turn fold on themselves
Questão 40
Questão
A peptide bond is a chemical bond formed between two amino acids
Questão 41
Questão
Stereoisomers are isomeric molecules that have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space.
Questão 42
Questão
A codon is the sequence of 3 consecutive nucleotides on a DNA or RNA strand. It either codes for a specific amino acid in a polypeptide or terminates the polypeptide chain
Questão 43
Questão
peptide = less than 50 amino acids in the linear sequence
polypeptide or protein = more than 50 amino acids in the linear sequence
Questão 44
Questão
Protein Structure
[blank_start]Primary structure[blank_end]
Linear sequence of amino acids.
[blank_start]Secondary structure[blank_end]
Backbone of the polypeptide chain folds into regular geometric structures.
• α-helix
• β-sheet
• Turns
[blank_start]Tertiary structure[blank_end]
Final folded form of the protein.
The native form of the protein.
[blank_start]Quaternary structure[blank_end]
Association of two, or more, polypeptide tertiary structures.
e.g.haemoglobin is comprised of two alpha and two beta polypeptide chains
Responda
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Primary structure
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Quaternary structure
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Tertiary structure
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Secondary structure
Questão 45
Questão
Lipids are composed of relatively simpler smaller molecules and they can form very large structures through non covalent associations
Questão 46
Questão
Unsaturated lipids have a double bond
Questão 47
Questão
When lipids are placed in an aqueous solvent, they cluster together forming microscopic lipid aggregates. In a lipid aggregate, the hydrophobic component of lipids are in contact with each other, while the polar head groups are in contact with the aqueous solvent.
Questão 48
Questão
Carbohydrate– ‘hydrate of carbon ’ Cn H2nOn (where n ≥3)
Questão 49
Questão
Oligosaccharides:
- 2 to 20 monosaccharides
-polysaccharides - ≥20 monosaccharides
Questão 50
Questão
Carbohydrate - structure
• General name
– according to number of carbons eg. trioses, tetroses,
pentoses, hexoses, heptoses
– according to type: aldose or ketose
• Aldoses
– aldehyde group in the structure
• Ketoses
– ketone group in the structure