,CHEM 210 Exam 1 | Biochemistry Exam Q&A |
Portage Learning
1. According to the Portage Learning CHEM 210 syllabus, which statement best describes the
primary focus of biochemistry as a discipline?
A) The study of chemical elements and their physical properties
B) The study of chemical processes and biomolecules that underlie living organisms
C) The study of geological formations and mineral composition
D) The study of mechanical forces in biological tissues
Correct Answer: The study of chemical processes and biomolecules that underlie living
organisms
Rationale: Biochemistry integrates chemistry and biology to study the chemical processes
and substances within living organisms, encompassing metabolism, enzyme catalysis, and
genetic information flow. Options A, C, and D describe unrelated fields such as inorganic
chemistry and geology.
2. Which cellular structure is present in prokaryotes but is NOT enclosed by a membrane?
A) Nucleus
B) Mitochondria
C) Nucleoid
D) Endoplasmic reticulum
Correct Answer: Nucleoid
,Rationale: Prokaryotes lack membrane-bound organelles; the nucleoid is an irregularly
shaped region containing the circular bacterial chromosome but is not membrane-enclosed.
The nucleus, mitochondria, and ER are membrane-bound organelles characteristic of
eukaryotes.
3. Which statement correctly distinguishes eukaryotic from prokaryotic cells?
A) Eukaryotes lack a nucleus; prokaryotes have a true nucleus
B) Eukaryotes contain membrane-bound organelles and a true nucleus; prokaryotes lack
these structures
C) Prokaryotes have linear chromosomes; eukaryotes have circular chromosomes
D) Prokaryotes contain 80S ribosomes; eukaryotes contain 70S ribosomes
Correct Answer: Eukaryotes contain membrane-bound organelles and a true nucleus;
prokaryotes lack these structures
Rationale: Eukaryotes have a true membrane-bound nucleus and organelles such as
mitochondria, ER, and Golgi. Prokaryotes lack these, with DNA in the nucleoid region.
Prokaryotic chromosomes are circular, and their ribosomes are 70S, while eukaryotic
cytoplasmic ribosomes are 80S.
4. In a eukaryotic cell, glycolysis occurs in which compartment?
A) Mitochondrial matrix
B) Cytosol
C) Inner mitochondrial membrane
D) Endoplasmic reticulum
, Correct Answer: Cytosol
Rationale: Glycolysis occurs in the cytosol of eukaryotic cells and the cytoplasm of
prokaryotes. The citric acid cycle and beta-oxidation occur in the mitochondrial matrix, and
oxidative phosphorylation occurs on the inner mitochondrial membrane.
5. Which subatomic particle determines the identity of an element?
A) Electron
B) Neutron
C) Proton
D) Positron
Correct Answer: Proton
Rationale: The number of protons (atomic number) uniquely identifies each element.
Neutrons affect the isotope but not the element's identity, and electrons can be gained or lost
without changing the element.
6. An atom gains two electrons. What happens to its charge?
A) It becomes positively charged
B) It becomes negatively charged
C) It becomes neutral
D) It loses mass
Portage Learning
1. According to the Portage Learning CHEM 210 syllabus, which statement best describes the
primary focus of biochemistry as a discipline?
A) The study of chemical elements and their physical properties
B) The study of chemical processes and biomolecules that underlie living organisms
C) The study of geological formations and mineral composition
D) The study of mechanical forces in biological tissues
Correct Answer: The study of chemical processes and biomolecules that underlie living
organisms
Rationale: Biochemistry integrates chemistry and biology to study the chemical processes
and substances within living organisms, encompassing metabolism, enzyme catalysis, and
genetic information flow. Options A, C, and D describe unrelated fields such as inorganic
chemistry and geology.
2. Which cellular structure is present in prokaryotes but is NOT enclosed by a membrane?
A) Nucleus
B) Mitochondria
C) Nucleoid
D) Endoplasmic reticulum
Correct Answer: Nucleoid
,Rationale: Prokaryotes lack membrane-bound organelles; the nucleoid is an irregularly
shaped region containing the circular bacterial chromosome but is not membrane-enclosed.
The nucleus, mitochondria, and ER are membrane-bound organelles characteristic of
eukaryotes.
3. Which statement correctly distinguishes eukaryotic from prokaryotic cells?
A) Eukaryotes lack a nucleus; prokaryotes have a true nucleus
B) Eukaryotes contain membrane-bound organelles and a true nucleus; prokaryotes lack
these structures
C) Prokaryotes have linear chromosomes; eukaryotes have circular chromosomes
D) Prokaryotes contain 80S ribosomes; eukaryotes contain 70S ribosomes
Correct Answer: Eukaryotes contain membrane-bound organelles and a true nucleus;
prokaryotes lack these structures
Rationale: Eukaryotes have a true membrane-bound nucleus and organelles such as
mitochondria, ER, and Golgi. Prokaryotes lack these, with DNA in the nucleoid region.
Prokaryotic chromosomes are circular, and their ribosomes are 70S, while eukaryotic
cytoplasmic ribosomes are 80S.
4. In a eukaryotic cell, glycolysis occurs in which compartment?
A) Mitochondrial matrix
B) Cytosol
C) Inner mitochondrial membrane
D) Endoplasmic reticulum
, Correct Answer: Cytosol
Rationale: Glycolysis occurs in the cytosol of eukaryotic cells and the cytoplasm of
prokaryotes. The citric acid cycle and beta-oxidation occur in the mitochondrial matrix, and
oxidative phosphorylation occurs on the inner mitochondrial membrane.
5. Which subatomic particle determines the identity of an element?
A) Electron
B) Neutron
C) Proton
D) Positron
Correct Answer: Proton
Rationale: The number of protons (atomic number) uniquely identifies each element.
Neutrons affect the isotope but not the element's identity, and electrons can be gained or lost
without changing the element.
6. An atom gains two electrons. What happens to its charge?
A) It becomes positively charged
B) It becomes negatively charged
C) It becomes neutral
D) It loses mass
