Cell Bio Overview Flashcards
What is the cellular membrane made of?
lipid bilayer
-Nonpolar Core (hyprophobic)
-Hydrophilic Heads on the outside
What is embedded in the membrane?
Proteins
What do the proteins on the cell membrane assist with?
- Regulating the transport of substances in and out of the cell
- Signaling external conditions to the cell
- Providing adhesive interactions
Integral Membrane Proteins
Reside within the membrane bilayer
Help with the movement of molecules across them and the transduction of energy and signals
Peripheral membrane proteins
Temporarily attached to the cell/organelle
Function in support, communication, enzymes, and molecule transfer in the cell
GPI-anchored protein
Involved in membrane protein transportation, cell adhesion, cell wall synthesis, and cell surface protection
protein that is anchored by a lipid anchor called Glycosylphosphatidylinositol (GPI).
Hydrophobic Alpha-helix
Responsible for interactions between most cells and their environment
Helical Bundles
A small protein fold composed of several alpha helices that are usually nearly parallel or antiparallel to each other
In membrane:
Blue = Polar
Red = NonPolar
(opposite when in the cytoplasm)
(Look at slide 5 of Handout 7 for a visual)
When can the translocation of secreted proteins begin?
They can be translocated even while they are still being synthesized by the ribosome
What makes up the Signal Recognition Protein (SRP)
proteins + rRNA
Where does the SRP bind?
binds to the signal sequence of the protein and directs docking of the translocon
What is the translocon
protein channel in rough endoplasmic reticulum (ER) membrane
What does the binding of the signal peptide to the translocon allow to happen?
widen the pore and allow the polypeptide to pass into the ER
Where does protein synthesis occur?
In the cytoplasm
What occurs in the Endoplasmic Reticulum?
folding of proteins
What assists in the folding of proteins in the ER?
Chaperones (Pepperonis) and Foldases
the chaperoninis are back!!!!
What is a vesicle and how does one form?
They are tiny sacs that transport material within or outside the cell
They form by pinching off from intracellular bodies and fuse with other membranes to combine contents
What is a Ligand? (when talking about a cell)
A chemical messenger released by a cell to signal an effect inside the cell
What are the three structural layers around a gram-negative bacteria?
Outer membrane
Cytoplasmic membrane
Periplasmic space
Escherichia coli
Model bacterial organism (E. coli)
Not all E. coli is the harmful E. coli we are told about
Bacteriocins
Toxic protein made by bacteria to kill closely related bacteria
Immunity Protein
Protein that provides immunity
(bacteriocin immunity proteins bind to the corresponding bacteriocins and render them harmless)
Plasmid
Self-replicating genetic elements that are sometimes found in both prokaryotic and eukaryotic cells
(NOT chromosomes or part of the host cell’s permanent genome. Most plasmids are circular molecules of double-stranded DNA)
BODER: small, circular, extrachromosomal DNA capable of replicating in cells.
Diploid
Having two copies of each chromosome and of each gene
Is having more than two copies of a genome common in animals?
No, it is extremely rare
(only one example has been found - an argentine rat) OLÉ
Polyploid
Having multiple sets of chromosomes per cell
Common in PLANTS
Germline
Reproductive cells producing eggs or sperm that take part in forming the next generation (in eukaryotic organisms)
Somatic
Cell making up the body
Germline passing of traits
Egg and Sperm undergo meiosis (forming a zygote)
Mutations are passed on to the next generation
Somatic passing of traits
Under mitosis
If a defect is developed early then all cells produced after that point by this ancestral cell will have the defect
Somatic mutations
A mutation that occurs in somatic cells and is not passed on to the next generation via the germline
Totipotent
A cell that can develop into all the different types of cells of the body (common in plants)
A single plant cell has the ability to form any part of the plant, reproductive or not
Stem cell
Example of a totipotent animal cell
Able to differentiate into multiple cell types
Nuclear envelope
Two concentric membranes that surround the nucleus of eukaryotic cells
Nuclear pores
How the nucleus and cytoplasm communicate with each other
Telomeres
Special repeated sequences that cap the ends of linear eukaryotic chromosomes
Centromeres
Region of the eukaryotic chromosome where the microtubules attach during mitosis and meiosis
How does yeast grow and divide?
Budding - a small bud emerges from the mother cell, enlarges until reaching a certain size, and then separates from the mother cell
What is a bud
The new asexual daughter cell of a yeast that forms as a bulge on the surface of the mother cell
What kind of cells does budding create?
Genetically identical cells because the genome divides by mitosis
What are yeast mating types?
a and alpha
(only an a plus an alpha can merge to form a new genetically unique diploid)
