Biological Cell Components

Question 1

What is Escherchia Coli?

Answer 1

This is a bacterium from the mammalian gut

Question 2

Describe the features of a bacterial cell

Answer 2

Outer membrane separates it from surroundings
Bulk is water
Controlled intracellular conditions
Contains info for procreation and to create 1D and 3D chemical components for its function

Question 3

Describe the thermodynamics of bacterial cellular processes?

Answer 3

Cellular processes are not thermodynamically spontaneous
Needs food and energy
Photosynthetic systems- sunlight provides food and energy (plants and bacteria)

Question 4

What are proteins?

Answer 4

Linear polymers of amino acids- defined sequence of 20 different amino acids they are made from
Active molecules in cells

Question 5

What is necessary for a properly functioning protein?

Answer 5

Requires precise 3D folds to carry out function

Question 6

What are nucleic acids?

Answer 6

Linear polymers of nucleotides

Question 7

Describe 2 types of nucleic acids

Answer 7

Includes DNA and RNA
DNA contains genetic information
RNA transfers genetic information- single stranded

Question 8

What are carbohydrates?

Answer 8

Linear and branched polymers of monosaccharides

Question 9

What is the function of carbohydrates?

Answer 9

Important in structure- cellulose and chitin

Important in energy storage- starch

Question 10

What is a lipid?

Answer 10

Structural role- phospholipid in cell membrane
Acts as long term energy storage- fats
Insoluble in water
Soluble in organic solvent

Question 11

What is a small metabolite?

Answer 11

A host of molecules- amino acids, nucleotides, saccharides, steroids
Water and metals are essential for life

Question 12

What is special about Ecoli regarding organic synthesis?

Answer 12

Ecoli can reproduce very fast- optimum conditions it can every 20 mins
Can do it in mild conditions- water, pH7, at cell temperature
Multiple parallel syntheses in same test tube

Question 13

Describe basic bacterial cell composition

Answer 13

70% water, 30% chemical

It contains proteins, small molecules, RNA, phospholipids, DNA and polysaccharides

Question 14

What is the central dogma?

Answer 14

Explanation of the flow of genetic information within a biological system
The flow for this process is one way

Question 15

Describe the basic steps of the central dogma

Answer 15

1. Replication of DNA
2. Transcription
3. Translation

Question 16

Describe the replication of DNA

Answer 16

Helicase unwinds DNA strand
DNA polymerase adds new nucleotides to the new strands
This is according to complementary base pairing
The two strands rewind

Question 17

Describe transription

Answer 17

DNA sequence is read by RNA polymerase

A complementary anti parallel RNA strand is formed

Question 18

Describe translation

Answer 18

mRNA is a single stranded copy of a gene
This is translated into a protein molecule
Linear amino acid chain folds to 3D protein
Linear gene codes for linear protein then folds

Question 19

Describe the function of proteins

Answer 19

Used in chemical reactivity- enzymes, energy transfer and capture, ligand binding
Used in signalling- membrane proteins, DNA and RNA binding proteins
Used for structure- collagen, silk
Used in mechanical, chemical activity and structure- muscles

Question 20

Where do proteins function?

Answer 20

Function in a biological environment- cellular temperature, aqueous solution or embedded in lipid membrane, pH7 in cell (varies outside cell)

Question 21

What is the role of cofactors?

Answer 21

Amino acids have limited chemical activity

Cofactors are used to increase amino acid chemistry

Question 22

What is meant by biosynthetic?

Answer 22

This means they are made within the living cell/ organism

Proteins are biosynthetic