Chapter 7

Question 1

Gene

Answer 1

A DNA sequence that encodes an RNA or protein product

Question 2

Transcription

Answer 2

Converting information encoded by a gene into its product

Question 3

Gene expression

Answer 3

The process by which the encoded information in DNA is converted into RNA or protein products

Question 4

Translation

Answer 4

Polypeptide chain assembled from amino acids specified by mRNA

Question 5

Codon

Answer 5

Three nucleotides that code for a specific amino acid or stop signal

Question 6

Exon

Answer 6

coding regions of genes that stay together in mRNA (spliced together after introns removed)

Question 7

Intron

Answer 7

non-coding gene regions taken out of mRNA after transcription

Question 8

Anticodon

Answer 8

complementary codons that bind to mRNA codons

Question 9

what is a homeotic gene and name one and what it does?

Answer 9

formation of body parts

tinman gene - codes for formation of the heart

Question 10

Where does transcription occur in Eukaryotic cells?

Answer 10

inside the nucleus

Question 11

Where does translation occur in Eukaryotic cells?

Answer 11

outside of the nucleus in the cytoplasm

Question 12

What are the three RNA molecules and what are their roles?

Answer 12

tRNA- delivers amino acids to ribosome during translation
mRNA- has a protein building message
rRNA- becomes part of ribosome

Question 13

What is the structural difference between DNA and mRNA molecules?

Answer 13

DNA uses ATGC

mRNA replaces thymine with uracil

Question 14

What are the basic steps of transcription?

Answer 14

> RNA and regulatory proteins bind to DNA at a promoter near the gene to be transcribed
RNA polymerase moves along the DNA, unwinding the helix to “read” the sequence of the template
RNA polymerase adds free RNA nucelotides to the growing RNA strand, according to the bases dictated by the DNA
When polymerase reaches the end of the gene, it releases the DNA and new RNA

Question 15

what are the basic steps of translation?

Answer 15

> Transcription in the nucleus, finished mRNA moves into cytoplasm through nuclear pores
Ribosomal subunits & tRNA converge on mRNA
-small ribosomal subunit binds to mRNA
-anticodon of tRNA base pairs with 1st AUG (methionine, start signal)
-last ribosomal subunit then joins small subunit
first tRNA is released an ribosome moves to next codon
another tRNA brings the next amino acid
process is repeated until a stop codon is reached
Then mRNA and protein detach from ribosome and subunits seperate

Question 16

How are mRNA molecules modified before translation?

Answer 16

Intons, exons, and poly-a tail ( 50-300 adenines put on end of mRNA; signal to export mRNA from nucleus)

Question 17

what is the basic structure and function of a ribosome?

Answer 17

ribosomes are made up of two subunits, one small and one large .
meet up and form an entire ribosome on an mRNA

Question 18

name the various types of mutations that can occur in DNA

Answer 18

insertion
deletion
substitution

Question 19

Basic biology of sickle cell anemia

Answer 19

a change in one amino acid in the protein product
Hemoglobin = 4 protein molecules: 2 alpha golbin and 2 beta golbin chains
the 6th amino acid in beta globin is valine (no charge) insteadd of glutamic acid (negative charge)