Eukaryotic Cellular Biology Flashcards
What are the two types of cancer genes ?
- oncogenes
- tumor suppressor genes
What are the order of steps for apoptosis ?
Disassemble cytoskeleton, break down nuclear membrane, break down genome, phagocytic digestion
What kind of mutation are oncogenes and tumor suppressor genes ?
oncogenes; gain of function mutations
tumor suppressor : Loss of function mutation
At what juncture point of mitosis is heavily regulated ?
Between G1 and S phase
What type of cell junction allows for exchange of cytosol between cells?
Gap junctions
What kind of amino acids must signal sequence for Secreted and membrane-bound proteins (that undergo through the secretory pathway,) be composed of ?
HYDROPHOBIC Amino acids
What are the four colligative properties ?
- Freezing point, 2. vapor pressure (both have depression)
- boiling point and 4. osmotic pressure (undergo elevation )
What kind of nephron allows for more effective concentration of urine ? Why?
LONGER NEPHRONS contribute to greater concentration of urine .
With longer nephrons, there is more surface area exposed to allow water and ions to diffuse into or out of the nephron
Differentiate between Hyperosmotic and hypo osmotic
Hyperosmotic : higher concentration of solute
hypoosmotic : lower concentration of solute
What is active transport ?
Active transport: when transport is AGAINST a concentration gradient using an energy source (Atp hydrolysis occurs)
What is facilitated diffusion ?
facilitated diffusion, which involves assisted movement DOWN a concentration gradient
what happens to freezing point when concentration of solutes increase ?
As the concentration of solutes increases with a solvent, its freezing point depresses (DECREASES)
Explain why salt will not diffuse out of salmon bodies
Salts will not diffuse out of their bodies; salts are IONIC and cannot cross cell membranes by diffusion
What is osmotic pressure ?
pressure required to resist movement of water by osmosis
Why can’t a gene for growth factor produce a protein in bacteria ?
mammalian genes contain introns that must be spliced out of the original RNA transcript before protein can be synthesized. (bacteria do not have introns and hence cannot undergo process)
Where are secreted peptides located ?
secreted peptide, it is found Extracellularly.
What does not cross cell membrane? How do Peptides function ?
Peptides do NOT usually cross the cell membrane. They must bind to an extracellular receptor which then triggers an intracellular signaling pathway to create their effect
What factors affect ability of molecule being able to cross membrane ?
- Size
- Polarity
small, hydrophobic molecules easily pass through membrane (whereas large hydrophilic do not)
What is a zygomen? How is it activated
a zymogen is an inactive -form of a cellular protein.
Most zymogens are activated by CLEAVAGE at a specific location within the amino acid sequence of the protein,
What are the basic amino acids ?
Basic amino acids (positive charge) such as lysine, arginine, and histidine
What are the acidic amino acids ?
Acidic amino acids (negative charge) are Aspartate and Glutamate