Muscle, Glucose Levels, Fatty Acid Tail, Protein, Membrane. Final Exam – Biochemistry
The key terms in this Bio-chemistry course include Muscle, Glucose Levels, Protein, Membrane, Hydrophobic, Fatty Acid Tail, Glucose, Molecules, Osmosis, Diffusion, Solute Concentration, Concentration Gradient, Electrochemical Gradient, ATP, Endergonic, Exergonic, Phagocytosis,
Olivia is a sixteen year old track star at a local school nearby. She arrived in the ER at 5:03 p.m. with complaints of extreme muscle weakness and loss of muscle coordination, particularly in her arms and legs! She told the attending physician that for the past few days, she had been pretty exhausted with little energy to do anything. Blood taken did show one particular abnormality. Her glucose levels were rather high although she was an athlete and did mention she ate carbohydrates the night before a race. However, this notion could be dismissed since she did not have a race in the past week. The doctors concurred that something else must be going on to render such high glucose levels (i.e. something was not breaking down these sugar molecules).
In addition, the doctors ordered for a muscle biopsy to be performed. After viewing the tissue sample under the microscope, the doctors saw that the muscle fibers were ragged red which contained mild accumulations of glycogen and decreased activity for the enzyme cytochrome c oxidase.
Which organelle’s function is likely disrupted?
Smooth ER
Rough ER
Peroxisomes
Mitochondria– correct
Lysosomes
Cytoskeleton
For a protein to be an integral membrane protein, it would have to be ________.
hydrophillic
hydrophobic
amphipathic, with at least one hydrophobic region- correct
exposed on only one surface of the membrane
Which characteristic of a phospholipid contributes to the fluidity of the membrane?
its head
cholesterol
saturated fatty acid tail
A double bond in the fatty acid tail- correct
What kinds of molecules pass through a cell membrane most easily?
large and hydrophobic
small and hydrophobic- correct
large polar
small and ionic
In which situation would passive transport not use a transport protein for entry into a cell?
water flowing into a hypertonic environment
glucose being absorbed from the blood
an ion flowing into a nerve cell to create an electrical potential
oxygen moving into a cell after oxygen deprivation- correct
Which of the following statements correctly describes osmosis?
Osmosis only takes place in red blood cells.
Osmosis is an energy-demanding or “active” process.
In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration. – correct
In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration.
The force driving simple diffusion is ________, while the energy source for active transport is ________.
a concentration gradient; ADP
a concentration gradient; ATP hydrolysis- correct
transmembrane pumps; an electrochemical gradient
phosphorylated carrier proteins; ATP
What is the combination of an electrical gradient and a concentration gradient called?
potential gradient
electrical gradient
concentration potential
Electrochemical gradient- correct
In what important way does receptor-mediated endocytosis differ from phagocytosis?
It transports only small amounts of fluid.
Does not involve the pinching off of membrane.
It brings in only a specifically targeted substance. – correct
It brings substances into the cell, while phagocytosis removes substances.
Which of the following molecules is likely to have the most potential energy?
Sucrose– correct
ATP
glucose
ADP
Olivia is a sixteen year old track star at a local school nearby. She arrived in the ER at 5:03 p.m. with complaints of extreme muscle weakness and loss of muscle coordination, particularly in her arms and legs! She told the attending physician that for the past few days, she had been pretty exhausted with little energy to do anything. Blood taken did show one particular abnormality. Her glucose levels were rather high although she was an athlete and did mention she ate carbohydrates the night before a race. However, this notion could be dismissed since she did not have a race in the past week. The doctors concurred that something else must be going on to render such high glucose levels (i.e. something was not breaking down these sugar molecules).
In addition, the doctors ordered for a muscle biopsy to be performed. After viewing the tissue sample under the microscope, the doctors saw that the muscle fibers were ragged red which contained mild accumulations of glycogen and decreased activity for the enzyme cytochrome c oxidase.
Which organelle’s function is likely disrupted?
Smooth ER
Rough ER
Peroxisomes
Mitochondria– correct
Nucleus
Lysosomes
Cytoskeleton
For a protein to be an integral membrane protein, it would have to be ________.
hydrophillic
hydrophobic
amphipathic, with at least one hydrophobic region- correct
exposed on only one surface of the membrane
Which characteristic of a phospholipid contributes to the fluidity of the membrane?
its head
cholesterol
saturated fatty acid tail
A double bond in the fatty acid tail- correct
What kinds of molecules pass through a cell membrane most easily?
large and hydrophobic
small and hydrophobic- correct
large polar
small and ionic
In which situation would passive transport not use a transport protein for entry into a cell?
water flowing into a hypertonic environment
glucose being absorbed from the blood
an ion flowing into a nerve cell to create an electrical potential
oxygen moving into a cell after oxygen deprivation- correct
Which of the following statements correctly describes osmosis?
Osmosis only takes place in red blood cells.
Osmosis is an energy-demanding or “active” process.
In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration. – correct
In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration.
Determine if each of the following is endergonic or exergonic.
Hydrolysis of ATP
exergonic– correct
A reaction causes an increase in disorder (entropy)
exergonic– correct
Dehydration reaction to build a triglyceride
endergonic– correct
A decrease in the disorder (entropy) of the cell
endergonic– correct
Catabolism of carbohydrates in muscle cells
exergonic– correct
Anabolism of peptide chains
endergonic– correct
Diffusion of glucose across the plasma membrane through a channel protein
exergonic– correct
Products have a higher free energy than the reactants
endergonic – correct
Reactants have a higher free energy than the products
exergonic – correct
The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following represents the activation energy required for the enzyme-catalyzed reaction in the figure?
a
b– correct
c
d