Cell Cycle Study Guide Flashcards
DNA is used to complete two two crucial cellular jobs. What are they?
What are the two major phases of the cell cycle? Which one is longer?
Interphase (longer) and Mitosis
What are the 3 subphases of Interphase? When is DNA replicated?
- G1(gap1): growth, protein synthesis, cell metabolism
- S(synthetic): DNA replication
- G2(gap2): preparation for division
Regarding DNA replication, define replication fork, replication bubble, DNA polymerase, DNA ligase, nucleotides, and semiconservative replication
- replication fork: the point where the DNA strands separate
- replication bubble: area of active replication
- DNA polymerase: positions complementary free nucleotides to form new strands; only works in one direction
- DNA ligase: fuses lagging strand that is being synthesized discontinuously
- semiconservative replication: one complete DNA strand is given to a new cell and one is kept in the old cell
- nucleotides: (ATGC) forming pairs on DNA strand
What types of cells perform mitosis efficiently? Which do not?
- Skin cells do mitosis efficiently
- nerve, skeletal, and cardiac cells do NOT
What are the 4 steps of cellular mitosis? Be familiar with what cellular events are happening within each step. Be prepared to look at a picture and identify the stage of mitosis occurring.
- Prophase: chromatin condenses into chromosomes and mitotic spindle is formed, nucleolus disappears
- Metaphase: centromeres are aligned at metaphase plate (equator of spindle)
- Anaphase: shortest, centromeres split, cytokinesis begins (cleavage furrow)
- Telophase: chromosomes uncoil back into chromatin, nucleoli reappear, spindles disappear
What is cytokinesis? When does it start? When is it completed?
The cell is splitting into two. Begins during late anaphase and ends in telophase.
What can occur when cells ignore mitosis stop signals?
cells duplicate rapidly and can cause tumors or cancer
What are proteins made of?
polypeptide chains that are made of amino acids
Define a gene. Define a codon.
- gene: a segment of a DNA molecule that carries the code for creating 1 polypeptide chain
- codon: 3 sequential bases that code for a particular amino acid (ex ggc=proline)
What is the role of RNA during protein synthesis?
- copies the DNA code and carries it through the cytoplasm to the ribosomes
- “go-between” molecule that links DNA to proteins
What are the two steps to making proteins? What happens in each step? Which happens first?
- transcription: DNA’s information is encoded in mRNA
- Translation: information carried by mRNA is decoded and used to assemble polypeptides
* dna -> RNA -> protein
(C COMES BEFORE L)
Define autophagy and apoptosis. Why would a cell practice autophagy? Or Apoptosis?
- autophagy: “self eating” process when cells malfunction but can recycle their parts
- disposal of unneeded proteins and organelles
- cell cannibalization in times of extreme stress
- cell restructuring during development - apoptosis: programmed cell death
- caspases (enzyme) degrade cell
- neatly destructs cancerous, infected, or old cells
Be confident in what cell differentiation or specialization means and how it occurs!
cell differentiation: the development of specific and distinctive features in cells (making them different from each other)
- in the embryonic stage, chemical signals channel cells into the specific developmental pathways by turning genes on / off.
Give an example of when hyperplasia might occur. How about atrophy?
- Hyperplasia: accelerated growth - increases cell numbers when needed (muscle growth)
- Atrophy: a decrease in size that results from loss of stimulation/lack of use (when you break a bone and the muscle shrinks)
