BCH4024 EXAM 1 QUESTIONS WITH
CORRECT DETAILED ANSWERS
(GRADED A+)
What are some characteristics of myoglobin? - Answer-It's a tertiary structure found in
the cytoplasm of cells. They will hold onto oxygen until it senses that there is a depletion
in the oxygen level, in which it will release the oxygen it's been holding. It has a
hydrophobic center with a heme and a polar outer layer.
Describe the heme structure - Answer-The gene holds an iron atom with a
protoperphyrn ring. This ring has 4 nitrogen atoms attach to the iron atom. A histidine R
group attaches to the iron as well to stabilize it. Finally, an oxygen will take up the 6th
orbital. Non-polar R groups surround the heme.
Explain why carbon monoxide is hard to remove from the heme - Answer-Carbon
monoxide has a linear bind to iron, which causes it to be a stronger bond and therefore
harder to remove. It binds about 20,000 better than O2, which does not have a linear
bond.
Explain how CO gets to the rest of the body - Answer-Hemoglobin takes the CO and
distributes it to the rest of the body, which leads the CO to replace the O2 being stored
in the myoglobin.
Describe the structure of hemoglobin - Answer-It's a tetramer. It has 2 identical alpha
chains and 2 identical beta chains which are all helixes. Each one has its own heme
group so it can hold up to 4 molecular oxygen.
Describe allosteric property - Answer-When O2 binds there will be one configuration of
the hemoglobin molecules, and when it releases, there will be a different conformation.
This is how the 4 proteins in hemoglobin communicate with each other.
How many binding affinities does myoglobin have? - Answer-One
Why does hemoglobin change its conformation - Answer-It changes conformation
depending on the type of environment it's in
How many states are there in hemoglobin? - Answer-2- R state and T state
Which state of hemoglobin has oxygen present? - Answer-R-state
Which state of hemoglobin doesn't have oxygen present? - Answer-T-State
, Where do you want high affinity of oxygen? - Answer-In the lungs
Where do you want low affinity of oxygen? - Answer-In the tissue
Since CO2 is not soluble, what does the body do? - Answer-1) have CO2 bind to
hemoglobin and take it to the lungs to be released
2) use it to make HCO3-
Why are enzymes essential to biochemical processes? - Answer-They increase the
reaction rate and show greater substrate specificity
Oixdoreuctases - Answer-Transfer of electrons (hydride ions or H atoms)
Transferases - Answer-Group transfer reactions
Hydroplanes - Answer-Hydrolysis reactions (transfer of functional groups to water)
Lyases - Answer-Cleavage of C-C, C-O, C-N, or other bonds by elimination, leaving
double bonds or rings, or addition of groups to double bonds
Isomerases - Answer-Transfer of groups within molecules to yield isomeric forms
Ligases - Answer-formation of C-C, C-S, C-O, and C-N bonds by condensation
reactions coupled to cleavage of ATP or similar cofactor
Enzyme structure characteristics - Answer-Hydrophobic interior
Polar AA in surface
AA side chains in active sites
- Acid residues (Asp & Glu)
- Base residues (Lys & His)
- nucleophilic residues (Lys, His, Cys, "ser"
What is an enzyme cofactor - Answer-They are used to do chemistry that is normally
impossible for functional groups
Cytochrome oxidase cofactor - Answer-Cu2+
Cytochrome oxidase, catalase, peroxide cofactor - Answer-Fe2+ or Fe3+
Pyruvate Kinase cofactor - Answer-K+
Hexokinase, glucose 6-phosphatase, pyruvate cofactor - Answer-Mg2+
Arginase, ribonucleotide reductase cofactor - Answer-Mn2+
Dinitrogenase cofactor - Answer-Mo
CORRECT DETAILED ANSWERS
(GRADED A+)
What are some characteristics of myoglobin? - Answer-It's a tertiary structure found in
the cytoplasm of cells. They will hold onto oxygen until it senses that there is a depletion
in the oxygen level, in which it will release the oxygen it's been holding. It has a
hydrophobic center with a heme and a polar outer layer.
Describe the heme structure - Answer-The gene holds an iron atom with a
protoperphyrn ring. This ring has 4 nitrogen atoms attach to the iron atom. A histidine R
group attaches to the iron as well to stabilize it. Finally, an oxygen will take up the 6th
orbital. Non-polar R groups surround the heme.
Explain why carbon monoxide is hard to remove from the heme - Answer-Carbon
monoxide has a linear bind to iron, which causes it to be a stronger bond and therefore
harder to remove. It binds about 20,000 better than O2, which does not have a linear
bond.
Explain how CO gets to the rest of the body - Answer-Hemoglobin takes the CO and
distributes it to the rest of the body, which leads the CO to replace the O2 being stored
in the myoglobin.
Describe the structure of hemoglobin - Answer-It's a tetramer. It has 2 identical alpha
chains and 2 identical beta chains which are all helixes. Each one has its own heme
group so it can hold up to 4 molecular oxygen.
Describe allosteric property - Answer-When O2 binds there will be one configuration of
the hemoglobin molecules, and when it releases, there will be a different conformation.
This is how the 4 proteins in hemoglobin communicate with each other.
How many binding affinities does myoglobin have? - Answer-One
Why does hemoglobin change its conformation - Answer-It changes conformation
depending on the type of environment it's in
How many states are there in hemoglobin? - Answer-2- R state and T state
Which state of hemoglobin has oxygen present? - Answer-R-state
Which state of hemoglobin doesn't have oxygen present? - Answer-T-State
, Where do you want high affinity of oxygen? - Answer-In the lungs
Where do you want low affinity of oxygen? - Answer-In the tissue
Since CO2 is not soluble, what does the body do? - Answer-1) have CO2 bind to
hemoglobin and take it to the lungs to be released
2) use it to make HCO3-
Why are enzymes essential to biochemical processes? - Answer-They increase the
reaction rate and show greater substrate specificity
Oixdoreuctases - Answer-Transfer of electrons (hydride ions or H atoms)
Transferases - Answer-Group transfer reactions
Hydroplanes - Answer-Hydrolysis reactions (transfer of functional groups to water)
Lyases - Answer-Cleavage of C-C, C-O, C-N, or other bonds by elimination, leaving
double bonds or rings, or addition of groups to double bonds
Isomerases - Answer-Transfer of groups within molecules to yield isomeric forms
Ligases - Answer-formation of C-C, C-S, C-O, and C-N bonds by condensation
reactions coupled to cleavage of ATP or similar cofactor
Enzyme structure characteristics - Answer-Hydrophobic interior
Polar AA in surface
AA side chains in active sites
- Acid residues (Asp & Glu)
- Base residues (Lys & His)
- nucleophilic residues (Lys, His, Cys, "ser"
What is an enzyme cofactor - Answer-They are used to do chemistry that is normally
impossible for functional groups
Cytochrome oxidase cofactor - Answer-Cu2+
Cytochrome oxidase, catalase, peroxide cofactor - Answer-Fe2+ or Fe3+
Pyruvate Kinase cofactor - Answer-K+
Hexokinase, glucose 6-phosphatase, pyruvate cofactor - Answer-Mg2+
Arginase, ribonucleotide reductase cofactor - Answer-Mn2+
Dinitrogenase cofactor - Answer-Mo
