Membrane proteins serve which of the following functions?
A. energy transduction
Which molecule regulates membrane fluidity, thereby regulating membrane permeability and affecting the function of proteins embedded in the membrane?
Which of the following is an attribute of membranes?
C. asymmetrical (inner face and outer face different)
The carbohydrate moieties of the plasma membrane glycoproteins and glycolipids are:
B. the sugar residues that form the glycocalyx
Proteins associated with the membrane through ionic interactions and located on or near the membrane surface are called _____.
D. peripheral proteins
In the cell structure the _____ provides support and controls the movement of cell organelles.
A. microtrabecular lattice
The microtrabecular lattice facilitates velocity of a synthetic pathway by binding enzymes of the pathway so that the product of one enzyme is released in close proximity to the next enzyme for which it is a substrate, including, for example, enzymes of ________.
C. fatty acid synthesis
The mitochondrion is the organelle responsible for:
C. producing most of the cell's metabolic energy (ATP).
Which of the following is selectively permeable, not porous, serving as a barrier?
C. mitochondrial inner membrane
Enzymes required for all of the following EXCEPT _____ occur within the mitochondrion.
Genes contained in mitochondria DNA code for proteins vital to the production of ATP and:
B. are inherited only from the mother
All of the following cells are capable of oxidative metabolism EXCEPT _____.
The nucleus is the cell organelle responsible for:
C. most of the initiation and regulation of cellular activity.
The entire genome for an organism is:
D. encoded within the nuclear DNA of each cell.
Which of the following nitrogenous bases is unique to DNA?
Transcription is the process by which:
B. the genetic information (base sequence) in a single strand of DNA is used to specify a complementary sequence of bases in an mRNA chain.
The rough endoplasmic reticulum (RER) is associated with:
D. protein synthesis
What part of a cell consists of a network of membranous channels that serves as a mechanism for communication between the inner and exterior portions of the cell?
A. endoplasmic reticulum
The smooth endoplasmic reticulum is found in most cells, but particularly in:
D. the adrenal cortex, gonads and liver
Lysosomes are the organelles that serve the cell by:
A. carrying out phagocytosis
Peroxisomes are the organelles that:
D. detoxify molecules such as ethanol by oxidization.
Correct terminal amino acid sequences on newly synthesized proteins function to:
B. direct proteins to their intended destination in organelles.
Receptor proteins on the cell surface:
D. modify the cell's response to its environment
Catalytic regulatory mechanisms that maintain balance in the regulation of metabolic pathways necessary for life of the organism include:
B. modulation of allosteric enzymes
Modulators alter the activity of regulatory enzymes by:
C. binding with allosteric sites and changing the shape of the enzyme.
Bcl-2 interferes with the apoptotic process by:
D. preventing efflux of cytochrome c from the mitochondrion
Most human enzymes are synthesized intracellularly and function within the same cell so that finding a particular enzyme active in the blood can indicate each of the following EXCEPT:
C. a healthy state
Which of the following have diagnostic value for disease states?
D. intracellular enzymes that express their activity in the bloo abnormally due to a disease process
Which of the following enzymes is used to diagnose hepatic disease?
D. alanine aminotransferase
Transfer of genetic information, physical exertion and anabolism are all examples of _____.
D. processes that require energy stored as ATP.
Which of the following nutrients is NOT considered an energy-producing macronutrient?
About 40% of chemical energy stored is in the form of high-energy bonds and about 60% is released as heat as the result of:
C. metabolism of macronutrients
The quantity of energy required by an endothermic reaction is _____ the quantity released in the reverse exothermic reaction.
B. the same as
The activation energy is defined as the:
A. energy needed to raise the energy of a reactant to its transition state.
When nutrients are systematically oxidized through a particular pathway such as glycolysis, and the net energy transformation is exothermic, individual reactions:
B. may be either endothermic or exothermic
The body's energy reservoir is mostly in the form of adenosine triphosphate because:
A. ADP can accept phosphate from high-energy donor molecules and then, as ATP, transfer it to lower-energy receptor molecules.
Each of the following is an energy-requiring process EXCEPT:
When a third phosphate group is added to ADP using inorganic phosphate, the type of reaction that occurs is _____.
An enzyme such as hexokinase facilitates the activation of glucose by _____ by ATP.
In what part of the cell does oxidative phosphorylation take place?
What is the major supplier of energy in metabolism?
D. ATP generated by oxidative phosphorylation
Most cellular reactions are reversible since the same enzyme that catalyzes the conversion also catalyzes the reverse reaction.
Systematic oxidation of glucose to carbon dioxide and water is also called:
Which of the following values for the free energy of hydrolysis (deta G0) indicates the most exothermic compound?
Dehydrogenases are a particular type of _____.
During cellular reduction, a molecule is reduced by:
C. accepting electrons
Human Nutrition Ch 1 - The Cell: A Microcosm of Life