Cellular structure and function

Question 1

State 3 differences between a prokaryotic cell and a eukaryotic cell

Answer 1

Prokaryotic cells have no nucleus whereas eukaryotic cells do have a nucleus.
Prokaryotic cells have a single circular chromosome whereas eukaryotic cells have multiple linear chromosomes.
Prokaryotic cells have a plasmid where as eukaryotic cells have no plasmid
Prokaryotic cells have no membrane bound organelles whereas eukaryotic cells do have membrane bound organelles.

Question 2

State 3 structures a plant (eukaryotic cell) has that an animal (eukaryotic cell) does not.

Answer 2

Plant cells have chloroplasts, cell wall and a permanent vacuole whereas animal cells do not.

Question 3

Describe the 3 parts of cell theory.

Answer 3

Cells are the basic structural and functional units of life.
All cells come from pre-existing cells.
All living things are made from one or more cells or from products of cells.

Question 4

Describe the differences between DNA and RNA

Answer 4

DNA has deoxyribose/Thymine/is double stranded whereas RNA has ribose/Uracil/single stranded

Question 5

Draw and label the monomer of a nucleic acid

Answer 5

Nucleotide (phosphate group, pentose sugar and nitrogenous base)

Question 6

Define the function of the nucleus

Answer 6

Contains DNA which controls cellular functions by coding for proteins

Question 7

Define the function of the mitochondrion

Answer 7

Site of aerobic cellular respiration

Question 8

Define the function of the ribosome

Answer 8

Translates the mRNA code into a ______ polypeptide.

Question 9

Define the function of the Golgi apparatus

Answer 9

Final modification and packaging of proteins into secretory vesicles

Question 10

Define the function of the rough endoplasmic reticulum

Answer 10

Folding _________ polypeptides into proteins and transport them into transport vesicles

Question 11

State the structure of the polymer DNA

Answer 11

Many nucleotide monomers joined together (for all DNA - single circular chromosomes, plasmids and linear chromosomes)

Question 12

Define the function of a transport vesicle

Answer 12

Transports proteins from the rough endoplasmic reticulum to the golgi apparatus

Question 13

Define the function of a secretory vesicle

Answer 13

Secretes the protein out of the cell by exocytosis

Question 14

Define the function of the plasma membrane

Answer 14

Regulates the inputs and outputs of the cell

Question 15

Define the function of a cell wall

Answer 15

Provides structure and support for the cell

Question 16

Define the function of a lysosome

Answer 16

Contains digestive enzymes for the destruction of unwanted cellular material

Question 17

Define the function of the cytosol

Answer 17

Fluid part of the cell where some chemical reactions occur

Question 18

Define the function of a chloroplast

Answer 18

Site of photosynthesis

Question 19

Define the function of the permanent vacuole

Answer 19

Stores cell sap

Question 20

What type of reaction is undertaken in the synthesis of a nucleic acid?

Answer 20

Condensation polymerisation (energy requiring, water is a product)

Question 21

What are the complimentary base pairing rules?

Answer 21

A-T (DNA, 2 Hydrogen bonds) OR A-U (RNA, 2 Hydrogen bonds)
C-G (DNA + RNA, 3 Hydrogen bonds)

Question 22

Define proteome

Answer 22

The entire set of proteins expressed by an organism at a given time.

Question 23

State two structures that are found in a eukaryotic animal cell but not in a eukaryotic plant cell.

Answer 23

Lysosomes and centrosomes

Question 24

What is a condensation polymerisation reaction?

Answer 24

The chemical elimination of water during the formation of polymers that requires energy

Question 25

What is a hydrolysis reaction?

Answer 25

Chemical addition of water

Question 26

What is the primary structure of a protein?

Answer 26

Sequence of amino acids in a polypeptide chain

Question 27

What bonds joins the primary structure of a protein?

Answer 27

Peptide bonds

Question 28

What is the secondary structure of a protein?

Answer 28

The primary structure folded into alpha helices, beta-pleated sheets or random folding

Question 29

What bonds hold the secondary structure of a protein together?

Answer 29

Hydrogen

Question 30

What is the tertiary structure of a protein?

Answer 30

The 3-D structure composed of folded secondary structures

Question 31

What bonds hold the tertiary structure of a protein together?

Answer 31

Hydrogen, ionic and disulfide bonds between the amino acid residual groups

Question 32

What is the quaternary structure of a protein?

Answer 32

Two or more polypeptide chains joined together

Question 33

How do you improve reliability?

Answer 33

More repeats

Question 34

What evidence is there to support the theory of Endosymbiosis?

Answer 34

Chloroplasts and mitochondria have their own DNA genome, bacterial ribosomal RNA, double membranes and size

Question 35

Describe the process that occurs in the nucleus during the production of an insulin protein.

Answer 35

Transcription occurs. This means that DNA unwinds, and RNA polymerase attached to the promoter region for the insulin gene.
DNA template strand is copied into pre-mRNA via complementary base pairing using RNA polymerase.
pre mRNA undergoes RNA processing. Introns are removed, a 5’ methyl G cap and 3’ poly-A tail are added to form mRNA.
mRNA from the insulin gene leaves the nucleus and goes to a ribosome.

Question 36

Describe the process that occurs at a ribosome during the production of a helicase enzyme.

Answer 36

Translation this means that
Ribosomes read the mRNA code for helicase.
tRNA brings the correct and specific amino acid to the ribosome.
tRNA anticodons are complementary and specific to mRNA codons.
Amino acids are joined together by a peptide bond, in a condensation polymerisation reaction, and a helicase polypeptide is formed.

Question 37

What happens to the SA:V ratio of an object as it increases in size?

Answer 37

SA:V ratio decreases/gets smaller

Question 38

Why do cells need a larger SA:V ratio?

Answer 38

To exchange materials efficiently (eg. diffusion)

Question 39

What is the promoter region of a gene?

Answer 39

A region that does not code for any proteins upstream of the gene