Flashcards in Chapter 2: Functional Organization Of The Cell Deck (38)
It is a digestive organelle.
When a gene is expressed, it
serves as blueprint for coding of proteins
Notes: Central Dogma of Life
DNA - mRNA - proteins
In the ribosome, the signal sequence is bound by the-
Signal recognition particle (SRP)
What specific protein acts as conduits for passive exit and entry of molecules?
Pumps use ATP, thus, active
Carriers facilitate transport across membrane or couple it with other molecule
Clathrin-coated pits are used to:
Transport vesicle molecules to specific organelles.
Notes: Clathrin is used in endocytosis and exocytosis while Coatamers are used to transport between ER and Golgi (COP-1 and COP-II)
One purpose of the lipid bilayer is:
To prevent water-soluble substances to cross the membrane.
Proteins responsible for organ transplant rejection
Which of the following proteins are not embedded but are tightly attached to either cytoplasmic or extracellular surface of the plasma membrane?
Answer: Peripheral Membrane Proteins
Note: Peripheral proteins can be removed by high or low concentration of salts while Integral Membrane Proteins are removed by detergents
The physical properties of the bilipid layer are dependent on its chemical makeup. The nature of the head groups of the lipid molecules would determine:
the density of the membrane
Membrane proteins have several functions. Which of the following statements are true?
Integrins are adhesion molecules that attach the cells to the extracellular matrix.
Phospholipids with long saturated fatty acids have ____ transition temperatures.
Which of the following best describes the function of rough ER in eukaryotic cells?
Insulin is a protein that is produced by certain pancreatic cells and secreted into the bloodstream. Which of the following choices best describes the route of your insulin from its production and exit from the cell?
Rough ER > transport vesicles > Golgi > transport vesicles > cell membrane
Which of the following signals directs the protein to the lysosomes?
Attachment of a terminal mannose-6-phosphate
Protein glycosylation occurs where?
Lumen of RER
Notes: Also in formation of disulfide bonds, GPI-linkages, and hydroxylation
Which of the following is NOT a characteristic of TIGHT JUNCTIONS?
Allow free-flow of cytoplasm between neighboring cells (It should NOT allow free-flow)
Unlike other intercellular junctions, it only attaches the cell to its neighbors at potential stress points.
A transmembrane protein creates tiny pores through which small molecules and ions pass through between adjoining cells.
It allows proteins to be synthesized and secreted continuously.
(as compared to Regulated pathway which is controlled by hormonal or neural signals)
Essential components of cillial mobility, flagella, centrioles, and spindle fibers
Assume you have generated a recombinant cDNA encoding a chimeric protein that contains a signal sequence attached to the amino terminus of the nuclear protein. Where would you predict that this protein would be localized?
It will enter the ER and eventually will be secreted from the cell
The location of the various synthetic pathway where lysosomal enzymes are segregated?
Which of the following is not a property of your SRP?
It contains a single peptidase activity
Notes: SRP is just a recognition particle. Its different from the Signal Peptidase protein
Function of integral membrane proteins?
Loss in these substances is a hallmark in metastatic tumor cells
Note: if cells do not adhere, they can travel through blood, thus, metastasise.
N-linked oligosaccharides are added in the:
Notes: ER for N-linked glycosylation Golgi for O-linked glycosylation
As they emerge from the ribosomes, signal sequences are recognized and bound by
Signal Recognition Protein (SRP)
The cell membrane is primarily made up of
What happens to Membrane Fluidity when there’s:
1. Insertion of cholesterol in between phospholipids.
2. Low temperature.
3. Presence of high temperature and cholesterol. Decrease
4. Presence of saturated fatty acids.
1. Cholesterol inserted between phospholipids > increases fluidity
2. Low temperature > phospolipids stay in place > decrease fluidity
3. High temperature with cholesterol > decrease fluidity (idk, mo ni sa RC pero murag wala ga make-sense)
4. High saturated fatty acid > phospholipids are more compact > decrease fluidity