Structure and Function of DNA
During what phase of the cell cycle does DNA replication take place?
Interphase
A single stranded piece of a DNA has the following bases: ACTGAG. What is the matching sequence on its RNA transcript?
UGACUC
What cell organelle makes protein?
Ribosome
What can cause a gene mutation?
Radiation (X-rays, sun, nuclear radiation), viruses, chemicals, errors during replication
But remember- Mutations are RANDOM
What do we call the monomer of DNA? What are its 3 parts? Which two parts form the backbone?
Nucleotide: phosphate group, sugar (deoxyribose), base (A, C, T, or G). The phosphate and sugar form the backbone.
What is the end product of DNA replication (be very specific!)
Two new molecules of DNA, each is identical to each other and to the original molecule.
Where does transcription happen?
Nucleus.
What are the monomers of protein called?
Amino Acids
Are all mutations harmful?
Helpful mutations: having ONE sickle cell gene makes you immune to the parasite that causes malaria. Lactase persistence. Neutral mutations:
Name the four bases present in DNA
Adenine, guanine, cytosine, thymine
A mistake in replication that does NOT cause a change in the amino acid sequence is called a...
silent mutation
This part of the process turns mRNA into a protein.
Translation.
Describe the difference between a point (substitution) mutation and a frameshift (deletion/insertion) mutation.
•One base (A, T, C, or G) is substituted for another
•One or more bases (A, T, C, or G) are added or deleted
What is the sugar present in DNA?
Deoxyribose
Name the two enzymes involved in DNA replication and describe their function.
Helicase: unzips/unwinds the DNA helix by breaking the bonds between the bases. DNA polymerase: makes DNA by adding complementary bases to the other side of each of the original strands.
Name 2 differences between DNA and RNA.
DNA: deoxyribose, thymine, double-stranded, made by DNA replication. RNA: ribose, uracil, single-stranded, made by transcription.
What is a codon
A 3 nucleotide sequence on mRNA that matches to a specific tRNA anticodon.
What is a chromosomal mutation? Give an example.
Alterations to a piece of a chromosome or a whole chromosome [e.g., Down syndrome (3 chromosome #21)]
What is a gene?
A sequence of nucleotides that codes for a protein
Name the three types of RNA and their functions:
mRNA- messenger- transcribes message from DNA, leaves nucleus
rRNA- ribosomal- makes up the ribosome
tRNA- transfer RNA delivers AA to mRNA codon
The bonds used to hold amino acids together during protein synthesis are called…
Peptide bonds. Polypeptide.
What are the 5 types of chromosomal mutations?
1.Deletion 2.Duplication 3.Inversion 4.Translocation 5.NonDisjunction