Cell Cycle & Genetic Expression

Identify and describe phases, meiosis & sexual reproduction, transcription w/ RNA & mRNA, translation & protein synthesis

What is the cell cycle

series of events that takes place in the cell as it grows and divides

Why is it a cycle and not a pathway

at the end 2 daughter cells can start the process over again

in eukaryotic cells what are the 2 major phases of cell cycle

1. Interphase

2. Mitotic Phase

Describe the Mitotic Phase

cell seperates its DNA into 2 sets and divides its cytoplasm forming 2 new cells

Describe the interphase

cell grows and makes a copy of its DNA

Where does the cell spend most of its time in the cycle

interphase

What happens during cell interphase

cell grows and replicates its chromosomes to prepare for cell mitosis

G1 - intrphase

cell grows larger, copies organelles, and make molecular building blocks for later steps

S - inteprhae

cell synthesizes a complete copy of the DNA in its nucleus and it also duplicates the centrosome

What do centrosomes do in S phase

helps separate DNA during M phase

G2 - Phase

cell grows, makes proteins and organelles, and begins to reorganize its contents in preparation for mitosis

What happens during M phase

the cell divides its copied DNA and cytoplasm to make 2 new cells

What does M phase involve

mitosis and cytokinesisWha

What is cytokinesis

physical process of cell division where a parental cell’s cytoplasm splits into two separate daughter cells

What is mitosis

cell division where a single parent cell divides to create two genetically identical daughter cells, each with the same number of chromosomes

What are the 4 stages of Mitosis

1. prophase

2. metaphase

3. anaphase

4. telophase

when does cytokinesis begin

when mitosis ends with just a little overlap

What happens during prophase (4)

1. chromosomes condense

2. spindle fibers start to appear

3. nuclear envelope breaks down

4. nucleolus disappears

What happens during ProMetaphase (3)

1. Chromosomes continue to condense

2. Mitotic spindle microtubules attach to kinetochores

3. Centrosomes move toward opposite poles

What happens during metaphase (3)

1. spindle fibers fully develop (on opposite sides)

2. chromosomes line up in middle

3. Each sister chromatid is attached to a spindle fiber

What happens during anaphase (3)

1. sister chromatids binding breaks down

2. Sister chromatids are pulled apart

3. Non-kinetochore spindle fibers lengthen elongating the cell

what happens during telophase (3)

1. Chromosomes arrive at opposite poles and begin to condense

2. nuclear envelope surrounds each set of chromosomes

3. Mitotic spindles break down

What happens during cytokinesis (2)

1. in animal cells a cleavage furrow separates the daughter cells

2. In plant cells a cell plate separates the daughter cells

Describe G0

some types of cells divided rapidly, so daughter cells immediately undergo cell division

What are chromosomes made of

2 sister chromatids

How many pairs of chromosomes does a human have

23 pairs: 22 autosomes and 1 pair of sex

What is DNA

deoxyribonucleic acid

What is a DNA polymer composed of

nucleotides/monomers

What are the 3 parts of a nucleotide monomer

1. sugar

2. Phosphate

3. nucleobase

A nucleotide =

Adenine

T nucleotide =

thymine

G nucleotide =

guanine

C nucleotide =

cytosine

What is DNA Replication

process by which th genome’s DNA is copied in cells

What must a cell do first before it can divide

copy/replicate it entire genome so each daughter cell end up with its own complete genome

What is a DNA Polymerase

main enzyme in the replication process

What is Meiosos

process where a single cell divided twice to produce 4 cells containing half the original amount of genetic information, used for production of gametes

What is the goal of meiosis

make daughter cells with exactly half as many chromosomes as the starting cell

goes from a ____ cell to ____ cell

diploid to haploid

what is gene expression

process of making proteins from DNA for cellular functionsW

What are the 2 steps of gene expression

transcription & translation

What is transcription

involves copying a genes DNA sequence to make an RNA molecule which is performed by the RNA polymerase enzyme, which link nucleotides to form an RNA strand

What are the 3 stages of transcription

1. initiation

2. elongation

3. termination

What is translation

mRNA is decoded and the cell reads the information to build a protein or subunit of a protein that contains a specific series of amino acids

In an mRNA what are the instructions for building a polypeptide

RNA nucleotides - A, U, C, G read as codons

How many codons are there for amino acids

61

What does the codon AUG specify

the amino acid methionine and acts as a start codon of proteins

What are 3 the stop codons

1. UAA

2. UAG

3. UGA

What is the collection of amino acid relationships called

genetic code