Chapter 13- RNA and Protein Synthesis Flashcards Preview

Bio > Chapter 13- RNA and Protein Synthesis > Flashcards

Flashcards in Chapter 13- RNA and Protein Synthesis Deck (29):
0

Scientists knew...

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

1

Genes contain...

Coded DNA that give the cell instructions for building proteins

2

Three major differences in RNA (versus DNA)

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

3

Three main types of RNA

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

4

Messenger RNA

Carries instructions from DNA out of the nucleus

5

Ribosomal RNA

RNA embedded in the ribosomes

6

Transfer RNA

Escorts an amino acid for attachment to growing proteins

7

RNA transcription

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

8

RNA polymerase

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

9

Promoters

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

10

RNA editing (purpose)

Lots of genes were transcribed that weren't needed

11

(RNA editing) introns

Parts of the code that are discarded

12

(RNA editing) exons

Parts of the code kept and spliced together in order

13

RNA editing (what it does)

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

14

Proteins

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

15

Nitrogenous bases in RNA

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

16

Codon

3 nitrogenous bases in mRNA

17

Anticodon

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

18

Reading codons

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

19

Translation

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

20

Central dogma of molecular biology

DNA-->RNA-->proteins

21

(Types of gene mutations) point mutations

Change one or a few nucleotides
Substitutions
Insertions
Deletions

22

(Types of gene mutations) frameshift mutations

Shift the sequence of codons

23

Chromosomal mutations

Changes the number or structure of chromosomes

24

Types of chromosomal mutations

Deletion
Duplications
Inversion
Translocation

25

Effects of mutations

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

26

Genetic disorders

Very harmful mutations

27

Helpful mutations

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

28

Mutations

Caused by mutagens- chemical or physical agents in the environment