DNA, Protein synthesis, Mitosis
. DNA Functions:
• Store and transmit ____________ information
• DNA is the molecule that makes up __________
• DNA provides the _________ for cells that tell the cell which _________ to make and when to make them.
• Every living thing has DNA within it
• Each type of cell uses different ________ (portions of DNA) as _______________ for its different functions.
Basic components of a nucleotide:
Deoxyribose- a 5 carbon sugar
Phosphate Group (p,o)
Nitrogen Base (n,c)
Types of Nitrogenous Bases:
1. Purines: ____ Rings of C & N
Types of Nitrogenous Bases:
2. Pyrimidines: __ Ring of C & N
DNA forms the shape of a “double helix”
It is often compared to a ladder or spiral staircase
Backbone of the ladder:
-these are held together by _____________
1. Ribosome Sugar
2. Phosphate group
Rungs of the Ladder:
-consist of ___ _________________ held together by __________ bonds.
2 nitrogen bases; hydrogen bonds
Base Pair Rules:
Prokaryotes lack a nucleus so the DNA is located in the cytoplasm of the cell. Most prokaryotes have a single circular DNA molecule. This is the cell’s _______________________.
The nucleus of a eukaryotic cell contains more than 1 meter of DNA
Before a cell divides it must make a copy of its DNA so that each new cell gets a complete copy. This process is called replication.
Occurs during the S phase of the cell cycle
1. The enzyme __________ unwinds the double stranded DNA molecule and breaks the ______________ bonds holding the base pairs together.
2. Single Strand Binding Proteins hold the DNA strands straight until the new DNA strands are made.
The two “old” DNA strands are used as templates to build two “new” __________________ strands using the base pair rules for adding nucleotides.
(5prime to 3 prime) antiparallel
3. The leading strand:
The enzyme primase begins the replication process by attaching a primer. Then the enzyme DNA polymerase helps to elongate (add nucleotides) continually in the 5’ to 3’ direction towards the replication fork to build the complimentary strand.
4. The lagging strand :
As the replication bubble opens, DNA polymerase can add nucleotides in short segments moving away from the replication fork. As the bubble continues to widen, another short strand can be synthesized. These short strands are known as Okazaki fragments.
5. These fragments are eventually joined by an enzyme called ligase.
. What are the components of a nucleotide?
Describe the backbone of the DNA ladder. What types of bonds hold it together.
It is held together by ribosome sugar and phosphate group. The bond is covalent
Describe the rungs of the DNA ladder. Include a description of the pairing rules and the bond type.
2 nitrogen bases held together by hydrogen bonds.
Adneine-Thymine= 2 hydrogen
Guanine- Cytosine = 3 hydrogen
Describe the difference between a purine and a pyrimidine.
Purine has 2 rings of (n,c) and Pyrimidines have 1 ring of (n,c)
1. List differences between DNA and RNA.
1. Ribose sugar instead of deoxyribose
2. Single stranded
3. Uracil replaces thymine
3. What are the types of RNA? What are their jobs?
1) Explain what happens during the process of transcription.
RNA polymerase binds to DNA and separates the DNA strands. RNA polymerase then uses one strand of DNA as a template from which nucleotides are assembled into a strand of RNA.
1. Explain what happens during the process of translation.
The MRNA nucleotide sequence to determine the amino acid sequence of the protein.
1. How many different kinds of bases can be found on DNA _______
2. What base is found on RNA but not on DNA? _____________
3. How many bases are in a codon? ______
4. On what type of RNA would you find the codon?
5. How many bases are in an anticodon?
6. On what type of RNA would you find the anticodon?
7. Explain the relationship between the codon and the anticodon.
8. How many amino acids are attached to a single transfer RNA? ________
9. Transcription occurs in the ____________________; translation occurs in the ________________________.
10. The process of making RNA from DNA is called ___________________ and it occurs in the _________________________
11. The process of assembling a protein from RNA is called ____________________________ and it occurs in the _________________________
12. Why is DNA called the “Blueprint of Life”
It is the instruction manual for your proteins
13. Given the following DNA sequence, transcribe the mRNA strand and then translate the amino acids:
DNA: UGU UCG UUG UAC CAA UUG GAG AAU UAU UGU AAC UAG
ACA AGC AAC AUG GUU AAC CUC UUA AUA ACA UUG AUC
CYS SER LEU TYR GLN LEU GLU ASN TYR TRY ASN STOP
During transcription, _______________ binds to DNA and separates the DNA strands. ________ _____________then uses one strand of DNA as a template from which nucleotides are assembled into a strand of RNA.
****Remember _________ in ______ and thymine in DNA*****
RNA polymerase; RNA polymerase; uracil; RNA
Promoters are regions in the DNA strand where RNA Polymerase will bind to the DNA. This is where transcription begins.
Similar signals in the DNA strand cause transcription to stop.
Introns: not involved in coding for proteins
Exons: involved in protein coding
Scientists are not sure what the purpose of the intron is. They do know that the RNA strand cuts introns before it leaves the nucleus.
Point Mutation: _____________ are considered point mutations because they occur at a __________ __________ in the DNA sequence.
Substitutions; Single point
Frameshift Mutations: _____________ and ___________ are considered frameshift mutations because they “shift” the reading frame of the genetic message.
The Genetic Code
Proteins are made by joining ________ _________ into long chains called _________________. Each polypeptide contains a combination of any or all of the 20 different amino acids. The ____________ of proteins are determined by the order in which different amino acids are joined together to produce polypeptides.
amino acids; polypeptides; properties
division of the__________
usually occurs at the same time as________
the cell membrane is drawn inward until the cytoplasm is pinched into equal parts.
A cell plate forms between the dividing nuclei- this gradually develops into a separating membrane.
1) Interphase: period of cell cycle between cell division
a) G1 phase: cell growth
b) S phase: chromosomes are replicated (DNA Replication)
c) G2 phase: the organelles and molecules required for
cell division are produced.
2) The M Phase:
a) Mitosis: division of the cell's nucleus
b) Cytokinesis: division of the cytoplasm
4 Phases of Mitosis: (PMAT) (job)
Prophase:chromosomes become visible, the centrioles move towards opposite poles of the nucleus, spindles attach to the chromosomes, the nuclear envelope begins to break down
Metaphase:Chromosomes align along equator of the cell
Anaphase: the sister chromatids separate into individual chromosomes and are moved apart
Telophase: the chromosomes gather at opposite ends of the cell and lose their distinct shape, two new nuclear envelopes will form
-during mitosis, there is a single division of the_____________that were duplicated during the S-phase of cell division
-at the end of mitosis __ daughter cells are produced
-mitosis is associated with organismal growth and____________________
-results in ___ diploid cells (in other words, chromosome number is maintained)
-the daughter cells produced are ________ _____to the original parent cell
-occurs in _______ cells (non-sex cells)