___ occur in bands around the entire circumference of the cell.
tight junctions
You step outside in the winter and your skin senses the cold air. BEFORE your body temperature drops, you wrap your arms around your body and start shivering. This prevents your body temperature from lowering and is an example of
feedforward regulation
consider the reaction: H2CO3 to CO2 + H2O
the reaction is catabolic
which of the following statements applies to autocrine regulation?
chemical regulators affect the same cell that produced it
Which of the following metabolic pathways does not require oxygen?
glycolysis
a certain protein receptor is capable of binding the neurotransmitter epinephrine but does not bind to the neurotransmitters dopamine, glutamate, or serotonin. This is because the receptor displays
specificity
the study of disease states in the body is called
pathophysiology
ammonia is
a waste product of amino acid metabolism
the process during which a protein is made from RNA is called
translation
which of the following is not true regarding the affinity a binding site has for a ligand?
it is due to covalent bonds between the ligand and the protein
before an amino acid can be broken down for energy
the amino group must be removed
which of the following statements is not true about allosteric proteins?
they are always activated when a modulator molecule binds to the regulatory site
physiology is the study of
how organisms function
a protein is found in blood that is produced by the pancreas and acts on the liver. That protein is probably
a hormone
the developmental process that leads to specialized cell types is called
differentiation
fats and oils are composed of
triglycerides
chemical messengers involved in local communication between cells are known as
paracrine substances
molecules that have some portions that are hydrophobic and others that are hydrophilic are called
amphipathic
which of the below occurs during fatty acid catabolism
beta oxidation
which body fluid compartments contains the largest percentage of total body water
intracellular fluid
cell membranes
consist primarily of phospholipids and protein
beta pleated sheets and alpha helices are examples of what level of structure in proteins?
secondary
macromolecules (biomolecules) form when monomers join together to make polymers. The reaction that accomplished this is
dehydration synthesis
RNA synthesis from a DNA template
is called transcription
which of the following are the most common effector cells in the reflex arcs
both muscle cells and glands are correct
___ consist of proteins linking the cytosols of adjacent cells
gap junction
a ligand is a molecule that binds to
a protein by noncovalent bonds
protein kinases
add phosphate groups to proteins
binding site A requires twice the concentration of ligand to achieve saturation as does binding site B. From this, one can conclude that
Binding site B has a higher affinity for the ligand than does binding site A
If the amount of sodium in the blood decreases, then a negative feedback control mechanism would be expected to
increase the amount of sodium in the blood
if a solution has a hydrogen ion concentration of 10^-9 the pH is
9
modulator proteins
bind to proteins and cause a conformational change that facilitates or inhibits the binding of the functional ligand to its binding site
consider the adage familiar to anyone who has observed oil spills in the ocean or has made a salad dressing: "oil and water do not mix." which of the following helps explain this observation
oil is hydrophobic
a major function of the plasma membrane is to
regulate the passage of molecules into and out of the cell
which of the following lists the levels of organization of the body in the correct order from smallest to largest?
cell, tissue, organ, organ system, organism
which of the following is the correct sequence for a regulatory reflex arc?
stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector
after spending several days at a high altitude, where oxygen pressure is low, a person will begin to produce more red blood cells, which enhances the ability of his/her blood to carry oxygen to the tissues. Which of the following control mechanisms best d
physiological acclimatization
enzymes
are catalysts in chemical reactions
the cell type that is specialized to communicate with other cells and control their activities is
nerve cells
which of the following is a way that the activity of an enzyme can be modified
all of the above
which of the below is not a type of connective tissue
blood
a chemical catalyst increases the rate of a reaction by
decreasing the energy of activation
which of the following is not true of the cytoskeleton
it refers to the cellular components of the bone
which of the following is not one of the four major categories of biological molecules
sugars
consider the following reversible reaction : M+N to Y+Z
At chemical equilibrium, which of the following is correct?
increasing the concentration of M will drive the reaction to the right
in transamination, the amino group of an amino acid is
transferred to a keto acid
what forces are responsible for establishing the secondary structure of a protein?
hydrogen bonds
substrate molecules bind to enzymes at the ___ sites
active
which of the following is not a primary function of proteins?
energy storage
name the above molecule
triglyceride
the conversion of ammonia into a less toxic substance produces
urea
you would expect a peptide bond to link
two amino acids
synthesis of lipids takes place at the
smooth endoplasmic reticulum
name the above molecule 2
nucleotide
a polysaccharide that is formed in the liver and muscle cells to store glucose is
glycogen
molecules that store and process genetic information are the
nucleic acids
carbohydrate molecules
are the body's most readily available source of energy