Chapter 13- RNA and Protein Synthesis

Question 0

Genes contain…

Answer 0

Coded DNA that give the cell instructions for building proteins

Question 1

Scientists knew…

Answer 1

What genes were made of (DNA) but not how they worked

Question 2

Three major differences in RNA (versus DNA)

Answer 2

The sugar is ribose not deoxyribose
Single stranded not double stranded
Contains uracil as fourth base not thymine

Question 3

Three main types of RNA

Answer 3

mRNA(messenger)
rRNA(ribosomal)
tRNA(transfer)

Question 4

Messenger RNA

Answer 4

Carries instructions from DNA out of the nucleus

Question 5

Ribosomal RNA

Answer 5

RNA embedded in the ribosomes

Question 6

Transfer RNA

Answer 6

Escorts an amino acid for attachment to growing proteins

Question 7

RNA transcription

Answer 7

Converts DNA code into RNA so the rest of the cell can understand and use it

Question 8

RNA polymerase

Answer 8

Synthesizes a single strand of RNA from a DNA template, similar to replication but now a pairs with u

Question 9

Promoters

Answer 9

Act as sites for the RNA polymerase to start (DNA is a big molecule)

Question 10

RNA editing (purpose)

Answer 10

Lots of genes were transcribed that weren’t needed

Question 11

(RNA editing) introns

Answer 11

Parts of the code that are discarded

Question 12

(RNA editing) exons

Answer 12

Parts of the code kept and spliced together in order

Question 13

RNA editing (what it does)

Answer 13

Let’s different cells use the same segment of DNA to code for different proteins (different effects)

Question 14

Proteins

Answer 14

Made of long chains of amino acids called polypeptides (20 different amino acids to choose from)

Question 15

Nitrogenous bases in RNA

Answer 15

Three bases in a specific order to code for one amino acid

Question 16

Codon

Answer 16

3 nitrogenous bases in mRNA

Question 17

Anticodon

Answer 17

3 nitrogenous bases in tRNA (base pairs for the codon)

Question 18

Reading codons

Answer 18

Must use chart on pg 367/311 of text to fully understand (will use example AGC)
Start with 1st nitrogenous base in the codon(a) find it in center of the chart
Moving away from the center of chart in a line from the 1st letter find the 2nd letter(g)
Moving still farther from the center find the 3rd letter (c)
The outermost part of the circle is the name of the amino acid the codon codes for
Methionine is the start code it is then read three bases at a time until the stop codon is reached

Question 19

Translation

Answer 19

A ribosome attaches to an mRNA strand and reads the codon
It finds the tRNA anticodon with the attached amino acid
Attaches amino acid to the growing polypeptide chain
Detached tRNA
repeats for next codon

Question 20

Central dogma of molecular biology

Answer 20

DNA–>RNA–>proteins

Question 21

(Types of gene mutations) point mutations

Answer 21

Change one or a few nucleotides
Substitutions
Insertions
Deletions

Question 22

(Types of gene mutations) frameshift mutations

Answer 22

Shift the sequence of codons

Question 23

Chromosomal mutations

Answer 23

Changes the number or structure of chromosomes

Question 24

Types of chromosomal mutations

Answer 24

Deletion
Duplications
Inversion
Translocation

Question 25

Effects of mutations

Answer 25

Only mutations in DNA of sex cells are passed on to the next generation
Most mutations have no effect on the organism

Question 26

Genetic disorders

Answer 26

Very harmful mutations

Question 27

Helpful mutations

Answer 27

Pesticide resistance

Polyploidy- plants with extra sets of chromosomes (results in stronger larger plants)

Question 28

Mutations

Answer 28

Caused by mutagens- chemical or physical agents in the environment