Lecture 15: HOW DO GENES MAKE A CELL?

Question 1

What is there within an individual?

Answer 1

Many different cell types

Question 2

What must each cell do?

Answer 2

Respond to the environment, make and break molecules, generate energy and maintain itself

Question 3

What are cells?

Answer 3

Very organised structures which contain different organelles. Dynamic and many different roles within

Question 4

How much of a typical human cell is protein?

Answer 4

50%

Question 5

How much of a typical human cell is lipids?

Answer 5

40%

Question 6

How much of a typical human cell is carbohydrates?

Answer 6

10%

Question 7

Where do building blocks of cells come from?

Answer 7

Plants (O2, CO2, light energy, water, minerals/nutrients in soil)

Question 8

What are the building blocks of cells?

Answer 8

Carbon chains, sugars, amino acids, sugar and base

Question 9

What do carbon chains form?

Answer 9

Lipids

Question 10

What do sugars form?

Answer 10

Complex carbohydrates

Question 11

What do amino acids form?

Answer 11

Proteins

Question 12

What do sugar and bases form?

Answer 12

Nucleic acid (DNA and RNA)

Question 13

What are the supramolecular assemblies?

Answer 13

Membranes, ribosomes and chromosomes

Question 14

What are the organelles?

Answer 14

Nucleus, Golgi, ER and mitochondria

Question 15

What is glycolysis?

Answer 15

Breakdown of glucose to pyruvate

Question 16

What is needed for glycolysis?

Answer 16

All enzymes needed

Question 17

What is the order of the central dogma?

Answer 17

DNA > transcription > RNA > Translation > protein

Question 18

How is the central dogma regulated?

Answer 18

Transcription control, RNA processing and stability, translation control, protein processing, protein activity and stability

Question 19

What does transcription control determines?

Answer 19

When and in what cells a gene is transcribed to produce mRNA

Question 20

What is the first step in determining how many individual proteins are produced in a cell?

Answer 20

Transcription control

Question 21

What does every cell have?

Answer 21

The same DNA and the same approximately 21,000 protein coding genes

Question 22

How many genes are expressed in any cell type?

Answer 22

About 11,000 to 17,000

Question 23

How many genes are expressed in all cells and needed for cellular function?

Answer 23

10,000

Question 24

How many genes are unique to a specific cell type?

Answer 24

About 1,000 to 2,000

Question 25

What do the unique genes do?

Answer 25

Make one cell type different from another

Question 26

What is done with the rest of the genes?

Answer 26

They are expressed in some but not all cell types

Question 27

What is transcription?

Answer 27

The process where a DNA sequence is copied (transcribed) into an RNA molecule

Question 28

What happens to a gene when it is transcribed?

Answer 28

It is 'turned on' or 'expressed'

Question 29

Transcription is a ...

Answer 29

key control point

Question 30

How is transcription a key control point?

Answer 30

If a gene is transcribed, it can be used to make a protein and if a gens is not transcribed in a cell, it can't be used to make a protein

Question 31

How many base pairs do we have?

Answer 31

3,200,000,000

Question 32

What are transcription factors?

Answer 32

Proteins that bind to a specific DNA sequence and control the rate of transcription (DNA to RNA)

Question 33

What are the key elements of a gene?

Answer 33

The regulatory/promotor region and the transcribed region

Question 34

Where is the regulatory/promoter region?

Answer 34

around 1000 to 2000 base pairs found before the start codon

Question 35

What is the regulatory/promoter region?

Answer 35

The DNA sequence at which transcription factors bind and recruit RNA polymerase

Question 36

What does the regulatory/promoter region determine?

Answer 36

How much a gene is transcribed

Question 37

What does the regulatory/promoter region contain?

Answer 37

Short sequences that transcription factors bind to

Question 38

What is the transcribed region?

Answer 38

Sequences of DNA that are copied into RNA (transcribed)

Question 39

What is done with the transcribed RNA (pre-mRNA)?

Answer 39

It is processed so that it can be translated (intron sequences are removed by splicing)

Question 40

When is a gene expressed?

Answer 40

When activator transcription factors are present and repressor transcription factors are absent

Question 41

What do transcription factors do?

Answer 41

Bind to the promoter region and recruit RNA polymerase

Question 42

What does having multiple transcription factors do?

Answer 42

Give precise control

Question 43

What must cells be able to do?

Answer 43

Respond to the conditions outside the cell

Question 44

How do the cells respond to conditions outside the cell?

Answer 44

By signalling molecules outside the cell binding to receptors on/in the cell and causing a change in activity of proteins inside the cell (signal transduction)