AS CORE CONCEPTS

Question 1

what are 4 characteristics of mitochondria?

Answer 1

• 2 membranes separated by inner membrane space folded to form cristae
• small circle of DNA so mitochondrion can replicate and code for proteins and RNA
• small ribosomes for protein synthesis
• solution containing compounds including lipids and proteins

Question 2

What is the function for mitochondria?

Answer 2

• produce ATP for aerobic respiration

Question 3

why is the endoplasmic reticulum connected to the nuclear envelope?

Answer 3

To transport materials

Question 4

What are characteristics of Rough ER?

Answer 4

• have ribosomes on outer surface so it can transport proteins made there

Question 5

What are the characteristic of smooth ER?

Answer 5

Synthesis and transports lipids

Question 6

what are the characteristics of Golgi body?

Answer 6

• vesicles containing polypeptides pinched off from RER and fuse with stack of membranes which constitute the Golgi body
• proteins are modified and packaged
• at the other end of the Golgi body the modified proteins are pinched off

Question 7

What are the functions of Golgi body?

Answer 7

• transport and store lipids
• produce glycoproteins
• secrete carbohydrates
• produce secretory enzymes to be packaged to secretory vesicles
• from lysosomes containing digestive enzymes

Question 8

what are the 4 characteristics of lysosomes?

Answer 8

• temporary vacuole surrounded by single membrane formed by being pinched off the Golgi body
• contain and isolate harmful digestive enzymes
• realise these enzymes when cell needs to recycle worn out organelles
• enzymes can also digest molecules that has been taken into cell

Question 9

What are the characteristics of DNA?

Answer 9

double helix
deoxyribose pentose
located in the nucleus
have ATCG base pairs

Question 10

What are the characteristics of RNA?

Answer 10

single nucleotide
ribose pentose sugar
Located in cytoplasm
AUCG base pairs
Short molecule

Question 11

What are the steps for DNA replication?

Answer 11

1. DNA helicase breaks hydrogen bonds between complimentary bases
2. This causes polynucleotides to separate
3. Free nucleotides line up between the complimentary bases and held by hydrogen bonds
4. DNA polymerase attaches to the molecules and moves down causing a phosphodiester bond to be formed between the activated nucleotides
5. The activated nucleotides lose 2 phospags groups
6. 2 copies of DNA is made that are semi conservative

Question 12

What is semi conservative replication?

Answer 12

When it has 1 new copy of dna and 1 original copy

Question 13

What is semi conservative replication?

Answer 13

When it has 1 new copy of dna and 1 original copy

Question 14

What is conservative replication?

Answer 14

Contains 2 new copies of dna

Question 15

What is the process of transcription ?

Answer 15

DNA helicase breaks hydrogen bonds between complimentary bases of dna strand causing 2 strands of
Complimentary rna nucleotides move into place and form hydrogen bond with the bases on exposed nucleotide on one dna strand
RNA polymerase joins nucleotides forming phosphodiester bond
Continue till the end of mRNA and its synthesised
DNA goes back to double helix structure and mRNA leave’s nucleus by pores and enters cytoplasm

Question 16

What is the process of translation ?

Answer 16

Small subunit of Ribosomes bind with the mRNA at start codon
tRNA molecule with an anticodon complimentary at the start codon attaches
This is held by hydrogen binds between base pairs on mRNA and tRNA
Second tRNA molecule moves into place
Peptide bond is formed between two amino acids
First tRNA molecule is released and keeps moving along mRNA and forms polypeptide
Reaches stop codon and polypeptide is released