What are the three main parts of a eukaryotic cell?
plasma membrane, cytoplasm, nucleus
Plasma membranes consist of what three components?
proteins, phospholipids, cholesterol
What are the non polar parts of a phospholipid?
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.
This is comprised of a pair of centrioles and pericentriolar materials.
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.
This is an organelle that modifies proteins produced elsewhere.
These are small flattened curved membranous sacs with bulging edges containing fusing and exiting vesicles.
This organelle contains strong oxidases that oxidize organic molecules?
Which organelle recycles worn out organelles?
degrade faulty cellular proteins
Which of the following separates the contents of the nucleus from the cytoplasm?
nuclear membrane (envelope)
What is the major function of a histone protein?
help organize coiling of DNA
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.
This portion of a DNA segment does not code for a protein.
This process describes the division of the cytoplasm.
The function of mitosis is
produce new cells with equal genetic material as the parent cell
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?
Mitochondria are organelles that...
extract energy from food
mRNAs are first transcribed as very long molecules with both coding and non codon portions. The coding portions are called...
This organelle modifies proteins produced in the rough endoplasmic reticulum
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.
Proteasomes are protein assemblies that...
degrade faulty cellular proteins
This structure assembles proteins for use in the cytoplasm of the cell
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...
The genes in this organelle are usually only inherited from the mother...
arise from blood-forming organs
a cancer of the lymphatic tissue
arise from epithelial cells
arise from melanocytes, pigmented cells in the skin
arise from muscle cells or connective tissues
anticodons are found on mRNA, but not tRNA
There are about 200 different cell types in the human body.
Cells are different because different cells contain different genes
Because elephants are larger, they have larger liver cells.
The glycocalix is always located on the cytoplasmic surface of plasma cell membranes.
programed cell death is called apoptosis
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.
Transmembrane proteins can act as channels or transporters
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.
Proteins made on ribosomes bound to the cytoplasmic surface of the endoplasmic reticulum are destined for the cytoplasm whereas proteins made on free ribosomes will be found within vesicles, several organelles, membranes, or secretion products of the cell