Semester 2 Final

Deoxyribose Nucleic Acid

What does DNA stand for?

A sugar molecule without an oxygen atom

What is Deoxyribose

store and use information to direct activities of cell and copy itself exactly for new cell that are created

2 primary function of DNA

nucleotides

Monomers of DNA

Polymers and 2 long strand of nucleotide monomers

What is the structure of DNA made of

5 carbon sugar called deoxyribose, phosphate group, and nitrogen bas

3 parts of nucleotides

Sugar molecule and phosphate groups

What is the same in every nucleotide?

Adenine (A), Guanine (G), Thymine (T), & Cytosine (C)

What are the 4 nitrogen bases

Adenine and Guanine

Which nitrogen bases are purines?

double ring of carbon and nitrogen atoms

What are purines composed of

Thymine and Cytosine

Which nitrogen bases are pyrimidines?

single ring of carbon and nitrogen atoms

What are pyrimidines composed of

A-T & G-C

Which nitrogen bases bond together

Nucleotide bonds to another

How does long strands form

Hydrogen bonds that attach the nitrogen bases

How do 2 strands bond together

deoxyribose and phosphate groups

What are the rails of the ladder made of

nitrogen bases

What are the rungs of the ladder made of

double helix

Another name for the twisted ladder

James Watson and Francis Crick

Who discovered the DNA structure

1953

When did they discover the DNA structure

nucleus

Where is DNA found in the cell

process of copying DNA in a cell

Replication

2 nucleotide chains separate by unwinding and serves as a template for the new chain

What happens during replication?

growth, repair, and reproduction

3 reasons you body replicates DNA

unwinds the DNA’s two chains of nucleotides

What does a helices enzyme do

bind to the separated chains and contracts a complementary chain of nucleotides

What does a polymerase enzyme do

2 identical copies of the original DNA molecule (one original chain and one new chain)

at the end of replication what is the product

5’ to 3’

Which way does DNA always replicate in?

glues lagging strand together

What is DNA ligase

continuous in 5’ to 3’ move towards replication fork

leading strand

discontinuously, moves away from replication fork

lagging strand

point at which the two strands of DNA are separated to allow replication of each strand (looks like a zipper)

Replication fork

Nucleus

Where is DNA located

copying a section of DNA into RNA

What is transcription

Nucleus of eukaryotes

Where does transcription occur?

converting information in the base sequence of RNA into amino acid sequence

What is translation

Ribosome in cytoplasm

Where does translation occur

mRNA, tRNA, & rRNA

3 types of RNA

messenger RNA (take info from DNA to ribosomes)

what does mRNA stand for

transfer RNA (brings amino acids to ribosomes)

what does tRNA stand for

Ribosomal RNA (ribosome - little circle where proteins made)

what does rRNA stand for

complementary

How is RNA synthesized compared to DNA

Uracil

What replace thymine in RNA

RNA polymerase

What enzyme is RNA made by

DNA at promoter

What does RNA polymerase bind to

unwinds DNA and makes complementary copy of one strand of the DNA

What does RNA polymerase do

signifies which strand is the template (coding) strand

What does the promoter do

transcription factors

What makes the promoter less/more active

proteins

What is mRNA used to make?

5’ cap, Poly A, Splicing

3 ways mRNA is modified

modifies G to tell where to start translation

what is 5’ cap

150-200 A to inhibit degradation

what is Poly A

cutting out the introns and putting together exons

what is splicing

non coding DNA

what are introns

coding DNA

what are exons

putting together the exons in different orders

what is alternative splicing

from nucleus to cytoplasm

where does mRNA go once made

anticodon of RNA that complements mRNA sequence

what does tRNA contain

three base pairs of mRNA

What is a codon

encodes for an amino acid

What does each codon do?

virtually all organisms use the same genetic code

What is universal

same amino acid may be encoded by multiple combinations of letters

What is redundant

AUG

What is the start of the codon

methionine amino acid

What do all proteins begin translation with

A site causes release factor to release tRNA at P site

what does a stop codon do?

polypeptide and mRNA gets released.

What happens when the ribosome disassembles

change in genetic material which changes the protein

What is a mutation

change in single base pair

Point mutations

redundancy in code inserts the same amino acid at that position

Silent

Inserts another amino acid

Missense

creates a stop codon, premature termination

Nonsense

causes change in the protein

Frameshift mutation

inserting one or more bases

Insertion

deletes one or more base pairs

Deletion

Cancer

abnormal growth of cells

what is cancer caused by

mutations and too much cell division, not enough apoptosis

\#1 risk factor of cancer

getting old

apoptosis

programed cell death

tumor

mass of cells with no function

3 types of tumors

benign, malignant, metastasis

Benign

abnormal cells remain at site (not cancerous)

Malignant

abnormal cells may spread to other areas of the body

Metastasis

cancer cells spread to new locations in the body

Causes of cancer

UV light, genetics, radiation, carcinogens

carcinogens

chemicals in cigarettes, environmental chemicals.

3 characteristics of cancer

lose contact inhibition, lose anchorage dependence, & immortal

lose contact inhibition

when it grows and hits a friend and divides

lose anchorage dependence

grow without being anchored to anything

Immortal

won’t die, supplied with nutrients

3 common ways to treat cancer

surgery, chemo, radiation

chemo

toxin that kills any fast reproducing cell

radiation

laser that only kills one area

cancer genes

oncogenes, proto-oncogenes

oncogenes

cancer causing genes

proto-oncogenes

normal, good genes which regulate cell division

tumor supressor genes

help prevent uncontrolled cell growth

example of tumor suppressor gene

p53 gene & BRAC1 & BRAC2

Is cancer inheritable

no

Why do cells divide

growth and repair

What is cell division

2 new daughter cells, genetically identical, reduces cell volume