Biology Chapter 2: Cellular Biology Flashcards
nuclear lamina
dense, fibrous network of intermediate filaments and proteins lining the inner nuclear membrane, providing structural support to the nucleus and anchoring chromatin.
Which intermolecular process primarily drives the formation of a bilayer when phospholipids are added to water?
Formation of bilayer is driven by entropy. Adding phospholipids to water decreases entropy because it forces water to arrange in an ordered, unfavourable cage-like structure (called a clathrate cage). Forcing lipids into a bilayer reduces this effect, increasing entropy (favorable)
Cyclins
regulatory proteins that control the progression of the cell cycle by activating cyclin-dependent kinases (CDKs) at specific checkpoints
Difference between totipotent, pluripotent and multipotent
Totipotent cells can form all body and extra-embryonic tissues, pluripotent cells can form all body tissues but not extra-embryonic tissues, and multipotent cells can differentiate into a limited range of cell types within a specific lineage.
Extra-embryonic: refers to tissues that support the development of the embryo but do not become part of the body of the organism itself. These include structures like the placenta, amniotic sac, and yolk sac
In translation, ribosomes read mRNA in what direction? What order is the protein synthesized?
mRNA is read in the 5’ to 3’ direction by the ribosome. Protein synthesized in the N->C direction
In DNA replication, DNA polymerase reads the template strand in what direction? And what direction is the new mRNA synthesized?
DNA polymerase reads the template strand in the 3’ → 5’ direction.
It synthesizes the new DNA strand in the 5’ → 3’ direction.
Which direction does mRNA polymerase read the template strand (anti-sense strand) and which direction is the resulting mRNA produced?
RNA polymerase reads the template strand (antisense strand) in the 3’ → 5’ direction.
It synthesizes the mRNA strand in the 5’ → 3’ direction.
Therefore, the mRNA is identical to the coding strand (the strand that isn’t transcribed) except mRNA has U instead of T
What is a 5’ cap?
Consists of a guanine nucleotide connected to the primary mRNA transcript via an unusual 5’ to 5’ triphosphate linkage. This guanosine residue is methylated at the 7 position directly after capping
The start codon for translation is positioned in what site of the ribosome during initiation?
The P position (peptidyl position)
The A site of a ribosome does what?
Binds incoming aminoacyl-tRNA carrying the next amino acid
The peptide chain grows from what position on a ribosome?
The P (peptidyl) position
What is contained in a complete culture medium?
The complete growth medium recommended for certain cell lines requires additional components which are not present in the basal medium and serum. These supplements help sustain proliferation and maintain normal cell metabolism and can include hormones, growth factors, and signaling molecules required for normal growth.
Nuclear export signals
are short sets of 4 hydrophobic residues in a protein that target the protein for export from the cell nucleus to the cytoplasm through the nuclear pore complex using nuclear transport
A nuclear localization signal
is an amino acid sequence that tags a protein for import into the cell nucleus by nuclear transport
Enzyme that creates a double-stranded DNA molecule from a single-stranded RNA molecule
Reverse transcriptase
