Organelles

Question 1

What is a metabolic compartment?

Answer 1

a separate place where the chemical processes of that cell occur

Question 2

What is the ultrastructure of a cell?

Answer 2

each cell type having an internal structure that suits its job

Question 3

Outline the different parts of a nucleus?

Answer 3

• the nuclear envelope
• Nuclear pores
• Nucleoplasm
• Chromosomes
• Nucleolus

Question 4

What does the nuclear envelope do?

Also describe it’s structure

Answer 4

it is a double membrane that surrounds the nucleus. its outer membrane is continuous which the endoplasmic reticulum of the cell . it controls the entry and exit of materials in and out of the nucleus and contains reactions taking place within it

Question 5

What does the nuclear pores do?

Answer 5

they allow the passage of large molecules, such as messenger RNA, out of the nucleus

Question 6

What is the nucleolus?

Answer 6

a small spherical region within the nucleoplasm. It manufactures ribosomal RNA and assembles the ribosomes.

Question 7

What are the functions of the nucleus?

Answer 7

• act as the control centre of the cell through the production of mRNA and tRNA and hence protein synthesis
• retain the genetic material of the cell in the form of DNA and chromosomes
• manufacture ribosomal RNA and ribosomes

Question 8

Draw and label the nucleus

Answer 8

Question 9

How is DNA stored in the nucleus?

Answer 9

within the nucleus, DNA is tightly packaged through association with histone proteins, forming chromatin

Question 10

What is the diagram for a mitochondria?

Answer 10

Question 11

What does the double membrane of the mitochondria do

Answer 11

it controls the entry and exist of material.

Question 12

What is the cristae and what does it do?

Answer 12

they are extensions of the inner membrane, which are folded, and provide a arge surface for the attachment of enzymes and other proteins involved in respiration.

Question 13

What is the matrix and what does it do?

Answer 13

it makes up the remainder of the mitrochondrion. It contains protein, lipids, ribosomes and DNA that allows the mitochondria to control the production of some their own proteins. Many enzymes involved in respiration are found int he matrix

Question 14

What is the job of the mitochondria?

Answer 14

To release the energy in glucose during aerobic respiration

ATP production

Question 15

How is the mitrochondrian adapted to cells that have a high level of metabolic activity.

Answer 15

the number an size of the mitochondria, and the number of their cristae are high

this is because they need to supply and plentiful amount of ATP

Question 16

What is the word equation for aerobic respiration

Answer 16

Glucose + oxygen —> Carbon dioxide + water ( + energy)

Question 17

Why is the plant cell wall relatively rigid and able to provide support for the cell?

Answer 17

Because, it mainly consists of bundles of long, straight cellulose molecules. The cellulose molecules lay side by side to form micro fibrils.

Question 18

What is ATP and what is it’s significance in respiration?

Answer 18

Adenosine triphosphate. Energy released by respiration ends up in the molecules if ATP. This is used in the cell to provide the enrgy for muscle contraction, active transport and building large molecules from small ones.

Question 19

What is the job of the chloroplasts?

Answer 19

Site of photosynthesis. Uses light energy to produce carbohydrates, starch, glucose, sugars and ATP

Question 20

Draw and label the chloroplast

Answer 20

Question 21

What does the chloroplast envelope do?

Answer 21

it is a double plasma membrane that surrounds the organelle. it is highly selective in what it allows to enter and leave the chloroplast

Question 22

What are the grana?

Answer 22

sacks of up to 100 thylakoids and is where the first stage of photosynthesis takes place

Question 23

What are thylakoids?

Answer 23

disc-like structures that have chlorophyll within them.

Some thylakoids have tubular extensions that join up with thylakoids in adjacent grana

Question 24

What is the stroma?

Answer 24

a fluid-filled matrix where trhe second stage of photosynthesis (synthesis of sugar) takes place.

Within the stroma are a number of other structures, such as starch grains

Question 25

How are chloroplasts adapted to their function of harvesting sunlight and carrying out photosynthesis?

Answer 25

the granal membranes provide a large surface area for the attachment of chlorophyll electron carriers and enzymes that carry out the first stage of photosynthesis. The chemicals are attached to the membrane in a highly ordered fashion

The fluid of the stroma posses all the enzymes needed to make the sugars in the second stage of photosynthesis

Chloroplasts contain both DNA and ribosomes so they can quickly and easily manufacture some of the proteins needed for photosynthesis

Question 26

What is the endoplasmic reticulum?

Answer 26

an elaborate, three-dimensional system of sheet-like fluid-filled sacs (cisternae), spreading through the cytoplasm of the cells. It continues with the outer nuclear membrane.

Question 27

What is the role of the rough endoplasmic reticulum?

Answer 27

provide a large surface area for the synthesis of proteins and glycoproteins

has ribosomes = makes proteins

provide a pathway for the transport of materials, especially proteins, throughout the cell.

Question 28

What is the difference in appearance for the two different types of endoplasmic reticulum?

Answer 28

the SER lacks ribosomes on its surface and is often more tubular in appearance

Question 29

What type of cells have a very extensive ER?

Answer 29

cells that manufacture and store and large quantities of carbohydrates, proteins and lipids.