UNIT C: Cell Division and Molecular Genetics Flashcards
DNA Structure
What does DNA stand for and what process does it govern?
- deoxyribonucleic acid
- governs the process of heredity
- Missing 3rd (OH) in diagram
DNA structure
What does RNA stand for and what is it involved in?
(hint: 2 things)
- Ribonucleic acid
- involved in: gene expression, and protien synthesis
- HAS THE 3RD (OH) molecule in diagram
DNA structure
What are chromosomes made up of?
(bonus: how many chromosomes do humans have?)
- DNA (long linear DNA + protien)
humans have 46 chromosomes
DNA structure
What did Griffiths Experiment (1928) include, and what did it prove?
(hint: a principle)
- What he did: He worked with two types of bacteria—one deadly (smooth, S) and one harmless (rough, R)—and injected them into mice.
- Key result: When he mixed dead S bacteria with live R bacteria, the mice still died! Somehow, the harmless R bacteria transformed into deadly S bacteria.
- What it proved: There is a **“transforming principle” ** (later found to be DNA) that carries genetic information and can be passed between bacteria.
- transforming princplie: dead pathogenic bacteria had passed on their disease causing properties to live non-pathogenic bacteria
DNA Structure
What did Hershey and Chase’s (1952) experimentation include, and what did it prove?
(hint: radioactive)
- radioactively labeled a viral protien coat (sulfur (s))
- radioactively labeled viral DNA (phosphorus (P))
- both were allowed to infect bacteria
- DNA had entered bacteria (NOT protien)
- THUS! - DNA is the heiriditary information
(ex. vials in video/diagram)
DNA Structure
What were Levene’s findings?
- nucleic acids are made up of long chains of nucleotides (polymers)
- each nucleotide is made up of a five-carbon sugar, a phosphate, and one of five nitrogen bases (A, T, C, G, + Uracil)
…
- Adenine & Gaunine = purines (2 rings)
Thymine, Cytosine & Uracil = pyrimidines (1 ring)
look at booklet diagram + replicate it
DNA Structure
How many rings does Adenine and Gaunine both have and what is that called
in relation to nucleotides
purines, 2 rings
imagine two hexagons connected
DNA Structure
How many rings does Thymine, Cytosine and Uracil all have and what is that called
in relation to nucleotides
Pyrimidines, 1 ring
imagine one hexagon
DNA Structure
What is a nucleotide made up of
(Levine)
- each nucleotide is made up of a five-carbon sugar, a phosphate, and one of five nitrogen bases (A, T, C, G, + Uracil)
- simply put:
- a five carbon sugar
- a phosphate group
- and a nitrogen base
look at booklet diagram
DNA Structure
Identify what nucelotides belong to either DNA or RNA
DNA
(ATCG)
- Adenine
- Thymine
- Cytosine
- Gaunine
RNA
(UAGC)
- Uracil
- Adenine
- Gaunine
- Cytosine
DNA Structure
What is Chargaff’s rule?
in relation to nucleotides
- The amount of Adenine is always equal to the amount of Thymine; The amount of Cytosine is always equal to the amount of Gaunine
(ex. notes table: A=20% T=20%, then C=30% & G=30%…. total = 100%)
look in notes (basic math)
DNA Structure
What nucleotides are bound together in a DNA double helix, and how?
VERY IMPORTANT TO KNOW
- Adenine and Thymine
- Cytosine and Guanine
- bound by HYDROGEN BOND
DNA Structure
What did (FRANKLIN) Watson and Crick conclude and how’d they determine it?
- Franklin used X-ray crstallography to conclude that DNA has a helical structure, and the nitrogen bases on the inside ans the backbone is on the outside
- Watson and Crick compiled the evidence and described the structure of DNA (double helix)
DNA Structure
What does it mean if DNA strands are “Anti-paralell”?
SOLIDIFY INFO LATER… IMPORTANT
- (up & down)
- 5 prime = 5 carbons ( has the “lollipop”/ PHOSPHATE)
- 3 prime = 3 carbons, has no phosphate
ex. diagram in booklet
DNA Structure
What are the actual strands/bases of DNA called
hint: twizzlers
Sugar-Phosphate Backbones
(the strands the nucleotides are attached to)
DNA Replication
DNA replication is? ___________ (+definition)
- semi-conservative
- def: each new molecule of DNA contains one strand of the new complementary DNA molecule and one original parent strand
look at booklet diagram
DNA Replication
Describe the INITIATION step in DNA replication
STEP 1
- starts the replication origin
- Helicase binds to and unwinds helix
- creating a replication bubble (replication fork)
video on classroom
DNA Replication
Describe the ELONGATION step in DNA replication
STEP 2
LOTSA INFO
TOP STRAND = LEADING
BOTTOM STRAND = LAGGING
DIRECTION MATTERS!
______________________________
- DNA Polymerase III adds new nucleotides (an RNA primer (by primase) acts as a strating point for elongation)
- can only take place in the 5 prime -> to 3 prime direction
- one strand is replicated continuously (leading strand)
- one strand is replicated in short segements (lagging strands)
- short segemnts called olcazaki fragments
- fragments are spliced together by DNA Ligase (ex. glue)
- DNA polymerase I removes RNA primers and replaces with complementary nucleotides (proofreading strand) -> no hydrogen bond means mismatch, size diff. means mismatch
look at notebook and classroom
DNA Replication
Describe the TERMINATION step in DNA replication
STEP 3
- completion of the new DNA strands and the dismantling of the replication molecules
DNA Replication
ex. of a correctly complementary DNA strand
no need to quiz yourself just remind urself
GAC TGA CCC CGC TAT TTG
CTG ACT GGG GCG ATA AAC
in booklet
DNA Replication
Helicase role in replication?
bind to the DNA at the replication origin and unwinds the helix
DNA Replication
replication bubble and fork defintion
bubble:
the unwound region of DNA
fork:
the Y shaped area where DNA is unwinding
initiation step
Protien Synthesis
Whats the general steps of protien synthesis
arrow diagram
NUCLEUS{ DNA (storage) ->(transcription)-> mRNA ->(translation)->protien (ribosome) }CYTOPLASM
“make” (related to gene expression)
Protien Synthesis - Transcription
Where does transcription take place
Nucleus
DNA Replication
The simplified steps of DNA replication
think diagram
- abc
- abc
- abc
Protien Synthesis - Translation
Where does translation take place?
Ribosome (into cytoplasm)
Protien Synthesis
Protien synthesis steps (written)
- Transcription (In the Nucleus)
- DNA is unzipped by RNA polymerase.
- mRNA (messenger RNA) is made using the DNA template.
- mRNA leaves the nucleus and moves to the ribosome.
- Translation (In the Ribosome)
- tRNA (transfer RNA) brings amino acids to the ribosome.
- Ribosome reads mRNA in codons (sets of 3 bases).
- tRNA matches codons with the right amino acids.
- Amino acids link together to form a protein.
DNA → mRNA → Protein.
