Unit 1.1 DNA structure

Question 1

Provide the function of the cell wall?

Answer 1

Provides structure and support to the cell.

Question 2

Provide the function of the plasma membrane?

Answer 2

Controls which Ions can enter or exit the cell. (described as selectively permeable)

Question 3

Provide the function of the cytoplasm?

Answer 3

Is the site of most of the cell’s chemical reactions.

Question 4

Provide the function of the vacuole?

Answer 4

Membrane-bound organelles, that contain the saps and sugars needed by the cell.

Question 5

Provide the function of the chloroplasts?

Answer 5

The sites of photosynthesis, containing the green pigment chlorophyll.

Question 6

Provide the function of the mitochondria?

Answer 6

The site of aerobic respiration. (double membrane)

Question 7

Provide the function of the nucleus?

Answer 7

Contains the cell’s genetic information, and is a membrane-bound organelle that Controls the cell’s activities.

Question 8

Provide the function of the ribosomes?

Answer 8

Sites of protein synthesis. Does not have a membrane. Made out of protein and rRNA molecules.

Question 9

Provide the function of the smooth endoplasmic reticulum?

Answer 9

a network of membranes inside a cell, through which proteins and other molecules are free to move.

Question 10

Provide the function of the golgi apparatus?

Answer 10

Helps to process and package proteins and lipid molecules, in particular the proteins that are being exported from the cell.

Question 11

Provide the function of the vesicles?

Answer 11

transport materials between membrane compartments.

Question 12

Provide the function of the rough endoplasmic reticulum?

Answer 12

has ribosomes on its surface.

Question 13

What is a DNA nucleotide and what does it consist of chemically?

Answer 13

A single basic repeating unit of DNA, consisting of a deoxyribose sugar (5 carbons) and phosphate group backbone, and one of four complementary bases.

Question 14

DNA nucleotides are joined together by _____________?

Answer 14

Strong covalent bonds

Question 15

What is meant by the term complementary base pairing?

Answer 15

Complementary base pairing refers to the weak hydrogen bonds formed between adenine and thymine or guanine and cytosine in a DNA molecule. Bases being complementary means that they can only bind to their specific complementary partner.

Question 16

What is meant by the term anti-parallel in relation to a DNA molecule?

Answer 16

This means that each strand in the DNA runs in an opposite direction, one strand runs in the 5’ to 3’ direction. Where the opposite stand will run in a 3’ to 5’ direction.

Question 17

State the structure of a DNA molecule?

Answer 17

Double-stranded helix.

Question 18

Where do cells store their genetic information? (within the DNA molecule itself)

Answer 18

In the sequence of bases of the DNA molecule.

Question 19

In a Deoxyribose sugar molecule within the nucleotide, where do the other chemical components lie?

Answer 19

The phosphate group lies on the 5’ end of the deoxyribose, the base lies on the 1’ end, and at the 3’ end of the deoxyribose the nucleotide will bond to another nucleotide by strong covalent bonds.

Question 20

What chemical bond holds two stands of DNA together?

Answer 20

Weak hydrogen bonds.

Question 21

Name the two types of cells?

Answer 21

Prokaryotes and Eukaryotes.

Question 22

What are the defining characteristics of a Prokaryote cell?

Answer 22

Prokaryotes are organisms that do not contain a true membrane-bound nucleus. Prokaryotes store their genetic information in large circular chromosomes. Prokaryotes may also contain circular rings of DNA called plasmids.

Question 23

What are the roles of the plasmids?

Answer 23

plasmids contain additional genes, that can be used to the advantage of the organism for instance to provide antibiotic resistance, increasing the chances of the organism’s survival.

Question 24

What are the defining characteristics of Eukaryotes?

Answer 24

Eukaryotes are organisms that contain a membrane bound nucleus. Eukaryotes also contain linear chromosomes that are tightly packaged around proteins.

Question 25

What are the proteins that linear chromosomes in Eukaryotes tightly package themselves around

Answer 25

Histone proteins.

Question 26

What makes Yeast a special Eukaryote?

Answer 26

Whilst Yeast contains a nucleus, and linear chromosomes wrapped around histone proteins, yeast also contains circular rings of DNA called plasmids.

Question 27

Can circular chromosomes be found in Eukaryotic cells explain your answer?

Answer 27

Yes Eukaryotes contain circular chromosomes: This is because circular chromosomes can also be found in the mitochondria and the chloroplasts (it is thought that these circular chromosomes within Eukaryotes were incorporated from early bacteria or eukaryotes).