Unit 5 BIIO

what happens in G1 phase of interphase and why

organelles duplicates, cell gets bigger because cytoplasm duplicates, and that causes cell to get bigger

What happens in S phase of interphase

DNA replication-each chromosome is replicated into 2 sister chromatids

What happens in G2 phase of interphase?

Additional growth, more proteins made, and centrioles form. Makes sure organelles are ready for cell divison

Mitosis and cytokne

Why do unicellular organism divide?

They divide for Reproduction called binary fission

why do multicellular organisms divide?

Renewal- cells that die from normal wear and tear

Repair: cells are damaged

Growth: Goes from a single fertilized egg to an organism

What are internal factors for uncontrolled cell growth/cancer?

Spontaneous mutations in DNA during our lifetime

What are external factors for uncontrolled cell growth/cancer?

Cigarette smoking,

poor diet+excericse

UV radiation (tanning)

Carcinogens create

cancer ccells

what are carcinogens

substance capable of causing cancer carcinogen in living tissue

Ex of carciongens

Tobbaco, Radon gas, asbestos, UV rays, alcohol

Cancer cells are

abnormal cells that divide without control due to mutations in DNA

Cancer cells may form

tumors

tumors are

abnormal mass of tissue.

Cancer cells may be killed by

Apoptosis

Apoptosis is

programmed cell death

Malignant tumors are

tumors that grow abnormaly and spread to other places in body. Considered cancerous. BADDDD

Benign tumors are

tumors where cells grow abnormally but stay in place in the body. Better news. Not cancerous

Treatments for tumors may be

screenings

surgery to cut out tumor

radiation to kill cells

chemotherapy to kill actively dividing ells

DNA macromlolecule

nucleic acid

DNA monomer

Nucleotide

Function of DNA

store genetic info

3 parts of the monomer

phosphate, nitrogen bases, 5 carbon sugar

parts of the DNA molecule

Nitrogen containing bases, Backbone

Shape of DNA moelcule

double helix

what is the DNA backbone made up of

phosphate groups and deoxyribose

Between Adenine and Thymine there are how many hydrogen bonds?

2

Between cytosine and guanine how many hydrogen bonds

3

Nitrogen containing bases are

adenine, Thymine, cytosine, guanine

Base pairing rules

A-T, C-G

Chargraff rules are

The Amount of Adneine is equal to the amount of thymine and the amount of cytosine is equal to the amount of guanine

Bases are connected by what bonds

hydrogen bonds

Backbone of DNA is connected by what bonds

covalent bonds

DNA is anti parallel. What does that mean

Means the strands run inopposite directions. The 2 strands of DNA are Anti-Parallel

Which nitrogen bases are double rings?

Adenine and Guanine

Which nitrogen bases are 1 ring?

Cytosine and thymine

Why does DNA replication happen

So each daughter cell receives  a complete set of chromosomes during cell division (mitosis/cytokinesis)

Where does DNA replication happen in eukaryotic cells

IN nucleus

When does DNA replication happen?

S phase

What is DNA replication controlled by?

Enzymes

What is the first step of DNA Replication? What is the enzyme that does this?

Helicase (an enzyme) Breaks H-Bonds between DNA bases. A replication fork forms and Primer is added to identify where replication should begin

What is primer?

a short, single-stranded RNA sequence synthesized by the enzyme primase, acting as the essential starting point for DNA polymerase to begin building a new DNA strand

What is the second step of DNA replication?

DNA polymerase( enzyme) adds free nucleotides - only works in the direction of 5’ to 3’. uses original DNA strand as a template. Proofreads and corrects mistakes

What is the third step of DNA replication?

Ligase(enzyme) Seals pieces on the lagging strand together

DNA breaks apart to be copied. True or false

True

What must be transmitted to a new DNA strands during replication to maintain genetic info?

Sequences of bases from existing DNA strands

Why is DNA replication called semi conservative

each new molecules one strand from it is old DNA and the other is New DNA

What does it mean when 2 strands of DNA are complemenatry

Sequence is paired based on their base pairing rules

The order of nitrogen bases determines the type of ______ that is assembled

protein

How many pairs of chromosomes does a human have

23 pairs

a segment of DNA that codes for a protein is called a

gene

How many chromomses in a body

46

What makes up each chromosome

DNA and 1000s of genes

What are the key events of cytokenisis

divison of cytoplasm

Cytoknesis in Animals is

animals: cleavage furrow forms and pinches cell membrane apart

cytokensis in plants is

cell plate forms and grows outward until it fuses inward in the cell wall

what happens when cell cycle isn’t rregulated

uncontrollable cell diviosn that leads to cancer

four main stages of mitosis

Prophase, metaphase, anaphase, telophase

what happens in prophase

chromatin condenses into visible, X-shaped chromosomes, the nuclear envelope breaks down, the nucleolus disappears, and the mitotic spindle begins to form

.

how many chromomses in the og cell

6

metaphase what happens

Chromosomes line up along the equator (metaphase plate) of the cell, and spindle fibers attach to the centromere of each sister chromatid.

Anaphase what happens

Sister chromatids are pulled apart by the spindle fibers toward opposite poles of the cell, becoming individual chromosomes.

Telophase

Chromosomes arrive at opposite poles, new nuclear envelopes form around each set of chromosomes, and the chromosomes decondense

what happens in interphase

a cell spends most of its life growing, performing normal functions, and replicating its DNA in preparation for mitosis

Leading strand

• DNA is replicated in one solid piece

Lagging Strand:

• Replicated  in small pieces called Okazaki fragments.

What is the enzyme that copies DNA?

DNA Polymerase