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
What is primary active transport ? What is required? Example?
Primary active transport: transport ions AGAINST their concentration gradient,
-hydrolyzes ATP to transport ions
ex: Na+/K+ ATPase
What is secondary active transport ?
Secondary active transport uses ion gradients (set up by primary active transporters) to move other molecules against their gradients;
What is facilitated diffusion ? Does it require energy ?
Facilitated diffusion is the PASSIVE movement of molecules across the membrane, DOWN their gradients, through a protein channel, and does not require energy input
What is simple diffusion ?
Simple diffusion is the PASSIVE movement of small, nonpolar molecules across the membrane,( NOT charged molecules)
How do Na-glucose co transporters move glucose across cell membrane ? Does it use ATP?
**sodium-glucose cotransporters rely on a Sodium gradient to move glucose across the cell membrane. **
While the sodium gradient is established by the Na+/K+ ATPase, the cotransporter itself does NOT hydrolyze ATP
How would Na+ K+ ATPase be affected with a decrease in ATP production ? What happens to Na+ and charge inside the cell ?
With a decrease in ATP production, the Na+/K+ ATPase function, which depends on ATP, will be INHIBITED
- This means that not as much Na+ will be pumped out of the cell, and intracellular Na+ would increase
-normally 3 Na+ ions are pumped out the cell while 2 K+ ions are pumped in. With the inhibition of the pump, would lead to less positive charge leaving the cell and more remaining inside. Thus, the cell would become less negative on the inside .
-since not as much Na+ is pumped out of the cell, secondary active transporters will have less of a Na+ gradient to work with, and thus will decrease in activity
a cell up regulation expression of Na+ K ATPASE would perform which actions ?
-Nuclear transcription and splicing, translation at the rough ER, protein modification, transport to the plasma membrane via a vesicle
Which processes occur in nucleus for eukaryotic cells ?
All eukaryotic cells perform transcription and splicing in the nucleus
What processes occur in cytoplasm for prokaryotic cells ? What does NOT occur?
prokaryotic cells undergo transcription in the cytoplasm but do not SPLICE their primary transcripts.
What is an example of facilitated diffusion
K + leak channel
How do you drive a gas out of solution ?
The best way to drive a gas out of solution is to LOWER the solubility of the gas by HEATING the solution (boiling)
Which elements in periodic table are soluble ?
Group I elements (Li+, K+) and Ammonium salts (NH4+) are soluble
What happens when Co2 is dissolved?
Dissolved CO2 turns into carbonic acid
How do you locate the pka of weak acid on graph?
The pKa of a weak acid is equal to the pH at the point half-way (along the horizontal axis) to the equivalence point of the titration with a strong base.
What is equivalence point for titration of strong acid with strong base
The equivalence point for the titration of a strong acid with a strong base is always at pH 7.
what are rules for knowing if chemical species Is acidic, basic or pH neutral ?
- The acidity of an element increases as one moves to the right or down the periodic table.
- The conjugate base (or acid) of a strong acid (or base) forms pH NEUTRAL solutions.
The conjugate base (or acid) of a weak acid (or base) is a weak base (or acid).
What is the dilution formula ?
molarity × volume)final = (molarity × volume)initial
Is HF or H2O more polar? Why?
HF is more POLAR due to greater difference in electronegativity between F and hydrogen( than between N or O and hydrogen)
What kind of process is dissociation of covalent bonds?
The dissociation of any covalent bond is an ENDOTHERMIC process (requires heat)
What kind of process is adding more water to form ion dipole reactions
process is so exothermic is because the addition of more water molecules allows for many more ion-dipole interactions between H+ and water and Cl– and water.
What happens to kw if products increase in a reaction ?
if concentration of products in a reaction increase, Kw will also increase
What is the relationship between concentration of H+ and pH?
a decrease in H+ will mean an INCREASE in pH
What kind of acid is protonated the most ? How does this affect pka?
the WEAKEST acid is always the most protonated regardless of pH.
The weakest acid is the one with the LARGEST pKa,
What happens to pka values of next dissociations of polyprotic acids (ex: H2CO3) ?
Successive H+ dissociations of polyprotic acids get weaker, with subsequently HIGHER pKa values.
ex H2CO3 —> HCO3- + H+ —> H + CO3 ^2-
. The pKa of HCO3– will be significantly higher than that of H2CO3. Therefore, the pKb of CO32– must be lower than the pKb of HCO3–.
What is the formula for finding pH of a weak acid ?
pH of weak acid:
Ka= [x]^2/ [acid] initial
[x] represents H+
What is p53? What are its functions ?
p53 is a tumor suppressor gene (TSG). It will INDUCE APOPTOSIS Though normally at low levels in cells, its production is scaled up when genetic damage or oncogene activity is detected, and if sufficient repair is not possible, p53 induces apoptosis.
p53 also has other functions. For example, it can activate DNA repair and arrest the cell cycle.
What kind of molecule is glutamine ?
hydrophilic, polar and neutral
which cells is transformation vs transfection used?
transformation used on Bacterial cells
while transfection used on eukaryotic cells
what organ is part of ectoderm?
Brain
What organs are part of mesoderm ?
blood, cartilage and bone
Which organs are part of endoderm?
the endoderm becomes the inner linings of different systems (gastrointestinal system, respiratory system, etc.) and glandular organs such as the liver and pancreas
Describe characteristics of fungi
Fungi are unicellular and non-motile eukaroyties
What are characteristics of lysogenic viruses ?
This would mean it requires a host to replicate and could encode for lysozyme or DNA hydrolase genes;
lysogenic viruses enter the lytic or productive cycles after they are activated and removed from the host genome.
What kind of cell wall do yeasts have?
cell wall made of CHITIN
