Test 1 Flashcards
substances with the highest ratio of extracellular fluid to intracellular fluid concentration for most mammalian cells:
sodium ions and chloride ions
the most abundant type of cell in the human body
red blood cell
substance has the highest intracellular fluid to extracellular fluid concentration ratio for most mammalian cells:
potassium ions
the time required for the red blood in the circulation to transverse the entire circulatory circuit when at rest
1 minute
exchange of substances between the cardiovascular system and the interstitial fluid occurs in the:
capillaries
how many cells are in the human body
100 trillion (but Karathanasis says 30 trillion)
human blood cells have a disk diameter of:
7,000 nm
0.007 mm
7 μm
homeostasis is the maintenance of:
constant concentration of ions in the blood.
stable pH.
stable body temperature.
positive feedback is often referred to as:
a vicious cycle because it leads to progressive instability and sometimes death.
What is an example of positive feedback within the body:
the clotting of blood
the most abundant substance in the human body is:
water being 60%
a large volume of blood is transfused to a person whose baroceptor (blood pressure control system) is not functioning, and arterial blood pressure rises from the normal level of 100 to 160 mmHg. If at another time the same volume of blood is infused into the same person when the baroceptor system is functioning and the arterial pressure increases from the normal level from 100mmHg to 120mmHg, calculate the gain of the baroceptor system in this person
-2
the cell membrane:
-contains cholesterol that regulated the fluidity of the membrane.
-carbohydrates are attached on the outside of cell membranes forming the glycocalyx, which gives negative charge
-is a bilayer approximately 7.5-10nm thick
what is NOT found in the cell membrane?
DNA
what is found in the cell membrane?
ion channel proteins
phospholipids
cholesterol
the rough endoplasmic reticulum:
contains a large number of ribosomes attatched to the outer surface.
is important in the synthesis of proteins and enzymes
lipid synthesis occurs in the:
smooth endoplasmic reticulum
proteins are sorted for their delivery to lysosomes, secretory vesicles, and the plasma membrane in the:
golgi apparatus
endocytosis:
can involve specialized protein receptors on the cell membrane
which of the following is true for both pinocytosis and phagocytosis?
involves the recruitment of actin filaments
ATP production:
-oxidation of 1mol of glucose releases 686 kcal of energy
-glycogen, is a large glucose polymer, which serves as storage of glucose
-typically glucose is converted to pyruvic acid and then to Acetyl CoA
-oxidative phosphorylation generates the majority of ATP molecules
the Krebs Cycle does NOT generate most of the ATP molecules
where does glycolysis take place?
cytosol
glycocalyx refers to:
the negatively charged carbohydrate layer on the outer cell surface
ubiquinone, an electron acceptor in the electron transport chain (oxidative phosphorylation) is found in the:
inner mitochondrial membrane
microtubules:
-are composed of proteins synthesized by ribosome
-are important in the cytoskeleton
-are important constituents of the centriole and the mitotic spindle
nucleus
distinguished eukaryotic cells from lower units of life such as bacteria and viruses
the following substances permeate the lipid bilayer more readily than water molecules
oxygen, CO2, N2, Non-polar sunstances
the following substances do NOT pass through the bilayer passively
urea, sodium, polar substances
translation:
-each codon codes for one amino acid
-transfer RNA acts as a carrier molecule during protein synthesis
-translation is initiated in the cytosol; protein is synthesized in ribosomes anchored to the endoplasmic reticulum membrane; protein is carried in membrane-bound vesicles to the golgi network for packaging
-multiple ribosomes can simultaneously translate a single mRNA molecule
apoptosis:
-is important to control the balance of cell density in tissues
-the suicidal programmed cell death, which involves proteolytic cascade (caspasses) leading to shrinkage, dissemblance of cytoskeleton and alteration of cell surface for recognition by macrophages
cell differentiation:
-not the result of the loss of genes. it is the result of the selective repression and/or expression of specific genes
-different from reproduction
-involves changes in physical and functional properties of cells as they proliferate
the sequence of events that occur during the synthesis and packaging of a secreted protein is:
translation. it is initiated in the cytosol; the protein is carried in membrane-bound vesicles to the cis-golgi apparatus; protein is then packaged for secretion in the trans-golgi network
the variation cell proteomes, or the proteins expressed by each cell type, reflects:
cell-dependent expression or repression of specific genes, or both
protein structure:
-the primary structure is a sequenced chain of amino acids
-the secondary structure is local folding of polypeptide chain into sheets
-the tertiary structure is the global folding of a protein chain
-the quaternary structure is a protein with more than one folded amino acid chain
-in the α-helix, the carbonyl oxygen of residue “i” forms a hydrogen bond with the amide of residue “i+4”