Chapter 3 Cell structure and Genetic Control

Question 1

What is a centriole

Answer 1

Cylindrical organelle - development of spindle fibers in cell division

Question 2

Plasma membrane function

Answer 2

Provides cellular structure
Seperates internal from external
Selectively permable
Allows communication between internal and external
Detects chemical messages arriving into cell

Question 3

Two types of membrane proteins

Answer 3

Integral:
Covalently bound to molecules in the membrane
Transmembrane
Can cross lipid bilayer many times

Peripheral:
Partially embedded
Non covalently bound to integral proteins

Question 4

What is the nucleus

Answer 4

Controls cell activity and contains DNA

Question 5

Golgi A

Answer 5

modifies proteins from ER and packages them into vesicles

Question 6

What is a lysosome

Answer 6

vesicle containing degestive enzymes - performs clean up

Destroy bacteria, damages organelles…

Question 7

What is the cytoskeleton

Answer 7

A network of interconnected microtubles which consist of protein filaments - function for movement and support

Question 8

How many amino acids are there?

Answer 8

20

Question 9

How many amino acids make a peptide

Answer 9

Less than 10

Question 10

How many amino acids make a polypeptide

Answer 10

10-100

Question 11

How many amino acids make a protein

Answer 11

More than 100

Question 12

What is a gene?

Answer 12

region of DNA that codes for a polypeptide

Question 13

List the order of Gene expression

Answer 13

Transcription
Splicing
Translation

Question 14

What does transcription do and where does it occur

Answer 14

1. DNA code is transcribed into mRNA - codons
2. Codons specify the amino acid sequence
3. mRNA carries the message from DNA

This occurs in the nucleus

Question 15

What does Splicing do and where does it occur

Answer 15

1. Removes Introns (non-coding region)
2. Splices exons together (coding regions)
3. mRNA exits nucleus and enter cytoplasm

This occurs in the nucleus

Question 16

What does Translation do and where does it occur

Answer 16

1. mRNA code is translated to tRNA
2. Each codon in the mRNA pairs with a complementary anticodon from tRNA.
3. This determines which amino acids are used as each tRNA carries an amino acid that detaches from the mRNA to form a polypeptide chain

This occurs in the ribosome