MH1010 Biochemistry Test With
Complete Solution
How are peptide bonds formed? - ANSWER They are formed by the
condensation of the alpha carboxyl of one amino acid and the amino group
of another
Define biochemistry - ANSWER Biochemistry is the study of chemical
substances and processes occurring in living organisms
Define PH
What is the ionic product of water? - ANSWER PH = -log[H+]
kw = [H+][OH-]
[H+] = [OH-]
Describe the PH scale - ANSWER Acid - PH of less than 7
Base - PH of more than 7
Neutral - PH of 7
What is the normal PH of blood?
What happens if there is changes in this PH? - ANSWER The PH of blood
should be 7.35 - 7.4
If PH drops below 6.8 - acidosis
If PH goes above 7.8 - alkalosis
,How does ATP carry energy? - ANSWER Phosphoryl groups are added via two
phosphoanhydride and one phosphoester bond
When these bonds are broken by the process of hydrolysis, energy is released
What is the difference between exergonic and endergonic? - ANSWER
Exergonic - energy releasing
Endergonic - energy requiring
Define the first law of thermodynamics - ANSWER Energy is conserved, it can
neither be created nor destroyed
Define the second law of thermodynamics - ANSWER In any closed system,
the entropy of the system will either remain constant or increase
Define enthalpy - ANSWER Enthalpy is the internal energy in a system - H
Define entropy - ANSWER Entropy is the randomness or disorder in a system
-S
Define Gibbs Free Energy - ANSWER This expresses the amount of energy
capable of doing work during a reaction at a constant temperature and
pressure - G
Write the equation for gibbs free energy - ANSWER Delta G - change in free
energy
Delta H - change in enthalpy
Delta S - change in entropy
T - absolute temperature
What does a negative delta G mean in terms of gibbs free energy? - ANSWER
,- Energy is released, exergonic
- Tend to occur spontaneously
What does a positive delta G mean in terms of gibbs free energy? - ANSWER
- Energy is consumed, endergonic
- Will not occur unless energy is supplied
What are the bonds found in each type of biomolecule? - ANSWER -
Carbohydrates - glycosidic bonds
- Proteins - peptide bonds
- Nucleic acids - phosphodiester bonds
What are stereoisomers? - ANSWER Stereoisomers are two chemicals that
have the same chemical and structural formulas but the geometrical
positioning of the functional groups in space differs
What are enantiomers? - ANSWER These are stereoisomers that mirror one
another and as a result cannot be superimposed on one another
What are essential amino acids? - ANSWER Histidine - H
Valine - V
Tryptophan - W
Threonine - T
Phenylalanine - F
Methionine - M
Isoleucine - I
, Leucine - L
Lysine - K
What is transcription? - ANSWER This is the DNA dependant synthesis of
RNA
What is translation? - ANSWER This is the process where mRNA sequence is
used to order and join amino acids into a polypeptide chain
Give the functions of the three different types of RNA - ANSWER rRNA -
found in the ribosome - plays a role in protein synthesis
mRNA - carries genetic information from the nucleus to the cytoplasm
during protein synthesis
tRNA - translates a sequence of mRNA into amino acids
What is the general structure of an amino acid? - ANSWER Amino acids
consist of ;
- An amino group, NH3+
- A carboxyl group, which dissociates to form a carboxylate ion COO-
- An alpha carbon, this is the carbon atom next to the carboxyl group
- A different side chain known as the R group
- A hydrogen atom
What are the amino acid classifications? - ANSWER 1 Non-polar, aliphatic R
groups
2 Aromatic R groups
Complete Solution
How are peptide bonds formed? - ANSWER They are formed by the
condensation of the alpha carboxyl of one amino acid and the amino group
of another
Define biochemistry - ANSWER Biochemistry is the study of chemical
substances and processes occurring in living organisms
Define PH
What is the ionic product of water? - ANSWER PH = -log[H+]
kw = [H+][OH-]
[H+] = [OH-]
Describe the PH scale - ANSWER Acid - PH of less than 7
Base - PH of more than 7
Neutral - PH of 7
What is the normal PH of blood?
What happens if there is changes in this PH? - ANSWER The PH of blood
should be 7.35 - 7.4
If PH drops below 6.8 - acidosis
If PH goes above 7.8 - alkalosis
,How does ATP carry energy? - ANSWER Phosphoryl groups are added via two
phosphoanhydride and one phosphoester bond
When these bonds are broken by the process of hydrolysis, energy is released
What is the difference between exergonic and endergonic? - ANSWER
Exergonic - energy releasing
Endergonic - energy requiring
Define the first law of thermodynamics - ANSWER Energy is conserved, it can
neither be created nor destroyed
Define the second law of thermodynamics - ANSWER In any closed system,
the entropy of the system will either remain constant or increase
Define enthalpy - ANSWER Enthalpy is the internal energy in a system - H
Define entropy - ANSWER Entropy is the randomness or disorder in a system
-S
Define Gibbs Free Energy - ANSWER This expresses the amount of energy
capable of doing work during a reaction at a constant temperature and
pressure - G
Write the equation for gibbs free energy - ANSWER Delta G - change in free
energy
Delta H - change in enthalpy
Delta S - change in entropy
T - absolute temperature
What does a negative delta G mean in terms of gibbs free energy? - ANSWER
,- Energy is released, exergonic
- Tend to occur spontaneously
What does a positive delta G mean in terms of gibbs free energy? - ANSWER
- Energy is consumed, endergonic
- Will not occur unless energy is supplied
What are the bonds found in each type of biomolecule? - ANSWER -
Carbohydrates - glycosidic bonds
- Proteins - peptide bonds
- Nucleic acids - phosphodiester bonds
What are stereoisomers? - ANSWER Stereoisomers are two chemicals that
have the same chemical and structural formulas but the geometrical
positioning of the functional groups in space differs
What are enantiomers? - ANSWER These are stereoisomers that mirror one
another and as a result cannot be superimposed on one another
What are essential amino acids? - ANSWER Histidine - H
Valine - V
Tryptophan - W
Threonine - T
Phenylalanine - F
Methionine - M
Isoleucine - I
, Leucine - L
Lysine - K
What is transcription? - ANSWER This is the DNA dependant synthesis of
RNA
What is translation? - ANSWER This is the process where mRNA sequence is
used to order and join amino acids into a polypeptide chain
Give the functions of the three different types of RNA - ANSWER rRNA -
found in the ribosome - plays a role in protein synthesis
mRNA - carries genetic information from the nucleus to the cytoplasm
during protein synthesis
tRNA - translates a sequence of mRNA into amino acids
What is the general structure of an amino acid? - ANSWER Amino acids
consist of ;
- An amino group, NH3+
- A carboxyl group, which dissociates to form a carboxylate ion COO-
- An alpha carbon, this is the carbon atom next to the carboxyl group
- A different side chain known as the R group
- A hydrogen atom
What are the amino acid classifications? - ANSWER 1 Non-polar, aliphatic R
groups
2 Aromatic R groups
