Exam 1 Study Guide Flashcards
Grocery store:
purge
bad tomatoes get tossed
Nucleic Acid class (deoxyribonucleic acid) carries the instructions, called genes, for building all of the proteins that a cell requires.
Chromosomes
DNA in the nucleus that is wrapped around proteins. 46 in each cell.
What state are chromosomes in before a cell divides?
They are in an uncondensed, string-like form. In order for cell division to occur, the DNA in each chromosome is compressed in to a more compact linear structure that is easier to maneuver during cell division.
How many genes does a single chromosome carry?
Hundreds of genes.
Sister chromatid
Copy of a chromosome that carries the same genes.
Where do sister chromatids attach to the original chromosome?
At the centromere. Because the centromere is not always located at the center of the chromosome, it can subdivide the chromosome into one long arm and one short arm.
DNA Replication
Precedes cell division. Steps include:
- The double stranded DNA molecule is copied first by splitting the helix down the middle and adding nucleotides to each side of the original parent molecule, maintaining the A-T G-C base pairings.
- Two new daughter DNA molecules
DNA Polymerase
Enzymes that assist in the synthesis of new DNA nucleotides. Reads the parents strand and adds whatever is complimentary and seals it to the previous new addition. VERY RELIABLE
What chemical bond forms behind the parent half of a helix and the new synthesized side?
Covalent.
Mutation
Occur when DNA polymerase make mistakes when facilitating base pairing of nucleotides.
Mitosis
asexual cell division that produces two daughter cells that are identical to their original parent cell and to each other.
Somatic Cells
any cell type that does not produce sex cells
Interphase
DNA replicates. There are three steps to interphase:
- G1: cell grows and organelles duplicate.
- S: DNA replicated (synthesis)
- G2: cell makes proteins needed to complete mitosis.
Prophase
DNA condenses into chromosomes. Microtubules form and are encoded by centrioles. Nuclear envelope begins to break down.
Metaphase
Chromosomes align at the middle of the cell. The microtubules grow long enough to attach to the chromosomes at their centromeres.
Anaphase
The microtubules contract and separate the sister chromatids from each other, pulling them toward the two poles of the cell.
Telophase
Nuclear envelopes re-form and chromosomes decondense.
Cytokinesis
A band of filaments contacts around the equator of the cell, causing two cells to form from the original parent cell.
Tumor Suppressors
Inspect newly replicated DNA.
Regulation of Cell Cycle
• Normal cells halt at checkpoints.
• Proteins determine condition of the cell.
• Cell must pass the checkpoints to proceed with cell division.
• Three checkpoints:
o G1
o G2
Metaphase
Organelles
perform specific jobs required by the cell and works in conjunction with other organelles to keep cell functioning properly.
Plasma Membrane
All cells are enclosed by a plasma membrane. Serves as a barrier that determines which nutrients are allowed into and out of the cell.
Nucleus
All eukaryotic cells contain a nucleus, a spherical structure surrounded by two membranes. Inside the nucleus is chromatin, composed on DNA and proteins.
Nucleolus
Ribosomes are synthesis.
Mitochondrion
energy-producing organelles surrounded by a double membrane.
Lysosome
is a membrane-enclosed sac of digestive enzymes that degrade proteins, carbohydrates, and fats.
Ribosomes
workbenches where proteins are assembled. Ribosomes are built in the nucleolus and shipped out of the nucleus through nuclear pores.
Rough ER
ER with ribosomes attached to it, which synthesize proteins that are useful around the cell.
Golgi
sorts proteins and sends them to their cellular destinations.
Centrioles
move chromosomes during animal cell division.
How do you decrease risk of cancer?
- Don’t use tobacco.
- Limit alcohol consumption.
- Eat low-fat, high-fiber diet (best one).
- Exercise regularly.
- Maintain a healthy weight.