Cell Cycle
What is the Cell Cycle?
a series of events that takes place in a cell as it grows and divides.
What is the scientific name and shape of DNA?
Deoxyribonucleic acid; Double Helix
Where does DNA replication begin? Where does the replication forks take place?
Origin of replication
Why is cell division important?
for growth and injury repair.
What is Cytokinesis and Mitosis
(separating out organelles and cytoplasm into two new cells);
(dividing DNA that was replicated in S phase)
What are the phases in the cell cycle?
Cell growth (G1), DNA Synthesis (S), Cell growth (G2), Mitosis, Cytokinesis (Mitotic phase)
Is DNA a macromolecule?
Yes; Nucleic Acid
What is DNA Helices?
- DNA helicase enzyme breaks the hydrogen bonds between nitrogenous bases.
- This opens up the DNA so that new strands can be made.
DNA-Genes-Chromosomes?
A chromosome is a condensed strand of DNA.
A section of DNA is called a gene. (Think of it like chapters in a book.)
The order of ATGC in a gene codes for a specific protein. These proteins keep the organism functioning.
Does Bacteria have a nucleus?
No
What are the phases of the Mitotic Phase?
Interphase, Prophase, Metaphase, Anaphase, and Telophase
What are the 4 different nitrogenous bases in DNA?
A, T, G, C
What is DNA Polymerase?
-DNA polymerase joins nucleotides to create the new strands of DNA.
-The original strands act as templates.
- The base pairing rules continue to be followed.
What is Genome?
the set of genes that are found in the nucleus of human somatic cells (body cells).
Who discovered the structure of DNA?
In the 1950s in England, James Watson and Francis Crick discovered the double helix structure of DNA. Watson and Crick get all the credit, but Rosalind Franklin had been taking x-ray crystallography images and that is actually what helped Watson and Crick to figure out the structure.
What happens in the Cytokinesis phase?
Cytoplasm is split
Varies in plant and animal cells
What are the building blocks of the monomer of DNA?
Nucleotide
Semiconservative Replication:
Resulting double helix consists of one strand of original DNA and one strand of new DNA.
What is Chromatin and Chromosomes?
Chromatin:
Loose DNA found in interphase; Genetic code can be more easily read to guide cell processes
Chromosomes:
Tightly condensed DNA formed at the beginning of mitosis; DNA instruction not read in this form; Easier to neatly separate during cell division
How long is the cell cycle?
A typical human cell might take 24 hours to go through the cell cycle and divide. Other fast dividing cells, like the lining of the intestine, may go through the cycle in 8-9 hours. The lining of the intestine regenerates every 5-7 days.
What do cells do after they divide into to cells?
- Some cells divide rapidly. So after they have divided, they quickly go through the cycle and divide again. Cells in a developing embryo or in a cancerous tumor may do this.
- Some cells may go through the cell cycle at a slower more typical rate.
- Other cells may be programmed to leave the cell cycle and stay in G0. Cells in this state just do their job and do not prepare for cell division unless they get a signal to do so.
What nitrogen bases are Purines and what ones are Pyrimidines?
A and G are Purines; C and T are Pyrimidines
Replication: Why does replication occur? (FACTS)
-There are trillions of cells in your body.
-There are about 3 billion base pairs of DNA in your genome.
-ALL of them must be accurately copied when any one of your trillions of cells divides.
What are Sister Chromotids?
When DNA replicates, two identical copies of DNA are created.
The two copies of DNA will attach to each other through a structure called the centromere.
DNA that has been replicated and then condensed forms sister chromatids.
What are Homologous Chromosomes?
-23 chromosomes come from the biological mother.
-23 chromosomes come from the biological father.
- The chromosomes are paired together