This is the only polar portion of a cholesterol molecule and it forms hydrogen bonds with the polar heads of phospholipids.
These membrane enclosed compartments or organized aggregates perform special functions in cellular growth, maintenance and reproduction.
This organelle is comprised of microfilaments, intermediate filaments and microtubules.
One type of human cell (e.g. spermatozoa) is capable of movement because it has this type of structure made of microtubules.
This membranous organelle contains ribosomes on its cytoplasmic surface, which synthesis proteins.
These are small flattened curved membranous sacs with bulging edges containing fusing and exiting vesicles.
Which of the following separates the contents of the nucleus from the cytoplasm?
nuclear membrane (envelope)
This is a long, maximally tightly coiled, molecule of DNA that contains genes-there are 46 in each body cell.
This binds to an amino acid and holds it in place on a ribosome until it is incorporated into a protein during translation.
Which of the following is not a function of the smooth endoplasmic reticulum?
stores proteins with large hydrophobic portions
Which membrane-bound organelle recycles worn out organelles and carries out intracellular digestion?
mRNAs are first transcribed as very long molecules with both coding and non codon portions. The coding portions are called...
Transport vesicles containing cargo and membrane proteins are constantly fusing and being formed from this organelle that adds non-amino acids groupings to to the proteins
The chamber of this organelle contains oxidative enzymes involving oxygen and free radicals that would otherwise damage cytoplasmic proteins.
The "beads on a string" model refers most appropriately to...
initial folding of DNA in chromatin structure
The three nucleotides that on mRNA that specify the position of a particular amino acid in a protein is specifically called a(n)
Which of the following accounts for the fact that humans have only about 25,000 genes but make over 100,000 proteins....
alternative splicing generates different mRNAs from the same pre-mRNA
Tay-Sachs disease and other diseases where certain materials accumulate in the cells is caused by a defect in this organelle...
A spherical cell with a radius of 8um has a higher surface volume ratio than a spherical cell with a radius of 4um
If a nucleus is not seen in a cell of a prepared slide of sectioned tissue, it means that cell does not have a nucleus.
With respect to membrane orientation, the inside surface of the membrane of a vesicle is analogous to the outside surface of a cell.
The membrane potential is negative on the outside membrane surface region relative to the inside membrane surface region.
Human sex cells (eggs and sperm) have half the number of chromosomes as other human cells in the body.