Transport
Diffusion and osmosis are examples of what kind of membrane transport?
Passive transport
What is an isotonic solution?
A solution that maintains the same osmolarity as the the inside of the cell, so volume doesn't change.
Mitosis results in how many daughter cells?
Two.
What is the functional unit of DNA?
Genes.
Define exocytosis and endocytosis.
Exocytosis: process where material is ejected from the cell. A vesicle fuses to the cell membrane and releases its contents outside of the cell.
Endocytosis: invagination of the cell membrane to form a vesicle containing extracellular fluid-in other words, bringing something into the cell.
What kind of substances can pass through the plasma membrane via simple diffusion?
Lipid soluble and nonpolar substances and very small molecules.
What is a hypertonic solution?
A solution that has a higher osmolarity than the inside of the cell, causing water to flow outside the cell-this causes the cell the shrink.
What are the phases that make up interphase?
G1, S, G2
What is the function of RNA polymerase?
It moves down the exposed DNA nucleotides and pairs each base with the complimentary RNA base.
What are tight junctions?
Integral proteins on adjacent cells that form an impermeable junction that encircles the whole cell. They prevent fluid and molecules from squeezing in between cells.
What 3 factors influence the speed of diffusion?
Concentration, molecular size, and temperature
Cholesterol plays what role in the plasma membrane?
Stability
How do telophase and cytokinesis differ?
Telophase is when the cleavage furrow is formed and the nucleus is reformed. In cytokinesis, the cytoplasm is split.
What is a codon and what role do they play in protein synthesis?
A codon is a unit of three bases that corresponds to a certain amino acid. They dictate where amino acids go, and when to start and stop translation.
What are gap junctions?
Transmembrane proteins, or connexons, form tunnels that allow small molecules to pass from cell to cell. Allows electrical signals to be passed quickly from one cell to the next.
How are symports and antiports different?
Symports move two substances in the same direction, and antiports move two substances in opposite directions.
What role does the plasma membrane play in cellular activity?
The plasma membrane controls what enters and exits the cell, and it acts as a barrier between extracellular and intracellular fluid.
What occurs during the G1, S, and G2 phases?
G1: growth and production of new organelles, structures, for DNA replication formed, replication of centrioles.
S: DNA replicated
G2: enzymes for cell division synthesized
What happens to the mRNA formed in transcription?
It leaves the nucleus and goes to a ribosome in the cytoplasm. The mRNA is run through the ribosome and is paired with amino acids to create a protein.
What are desmosomes?
Rivet-like cell junction formed when linker proteins, or cadherins, of neighboring cells interlock like zipper. They reduce the possibility of cells tearing under pressure.
How does the Sodium/Potassium(Na+/K+) pump function?
It moves one type of ion into the cell against the gradient, and another type of ion out of the cell against the gradient.
State the two types of membrane proteins and their function.
Integral proteins: transport proteins(channels and carriers), enzymes or receptors.
Peripheral proteins: function as enzymes, motor proteins(when cell changes shape), and help with cell-to-cell communication.
What occurs during the phases of mitosis(prophase, metaphase, anaphase, and telophase)?
Prophase: chromosomes formed, microtubules formed from centrioles, centrioles move to opposite poles, nuclear envelope dissolves.
Metaphase: chromosomes aligned at the equatorial plate
Anaphase: spindle fibers move sister chromatids towards opposite poles.
Telophase: arrival of chromosomes at each pole, begin to uncoil, new envelope forms around chromosomes.
Summarize the three steps of translation: initiation, elongation, and termination.
Initiation: complex formed between mRNA and tRNA; start codon attaches to ribosomal P site.
Elongation: the rest of the amino acids are attached through complimentary pairing of anticodons with codons.
Termination: stop codon ends translation and protein is released from ribosome.
List places in the body where gap junctions, desmosomes, and tight junctions are found.
Gap junctions: cardiac and smooth muscle, embryonic cells
Desmosomes: cardiac muscle, bladder
Tight junctions: skin, digestive system