biology 1.4 organelles

Question 1

where are ribosomes found

Answer 1

both prokaryotic and eukaryotic cells

Question 2

describe ribosomes

Answer 2

they lack a membrane and are extremely small about 0.03 micrometers in diameter

Question 3

what is the function of a ribosome

Answer 3

the function of a ribosome is to convert a code from the nucleus (mRNA) into a functional protein. protein synthesis.

Question 4

where in the cell are ribosomes found

Answer 4

they are found free-floating in the cytoplasm or in an eukaryotic cell they are attached to the membrane of the endoplasmic reticulum

Question 5

why are proteins needed

Answer 5

• repair
• growth
• maintaining cell structure
• hormones
• transport oxygen (haemoglobin’s)
• digestive enzymes

Question 6

what are proteins made of

Answer 6

amino acids

Question 7

what is the nucleus

Answer 7

the nucleus is a distinct spherical structure that is enclosed within a double membrane known as the nuclear envelope/nuclear membrane.

Question 8

what do NPCs do in an animal cell

Answer 8

control the exchange of materials between the nucleus and the cytoplasm

Question 9

how is a functional protein made

Answer 9

the polypeptide chain of amino acids assembled at the ribosomes is folded into a 3d shape to make a functional protein

Question 10

what are the functions of the nucleus

Answer 10

• control of DNA replication during cell division
• repair of genetic material
• control of the metabolic actives of a cell

Question 11

what is the nucleolus

Answer 11

the nucleolus is composed of RNA and its function is to produce the RNA that forms part of the ribosomes.

Question 12

what is the mitochondria

Answer 12

it is an organelle that is the major site of ATP production

Question 13

what is the function of the mitochondria

Answer 13

to convert chemical energy (glucose) into a useable form (ATP)

Question 14

what produces ATP

Answer 14

plant and animal cells produce ATP in the process of cellular respiration

Question 15

how can mitochondria be seen

Answer 15

with an electron microscope

Question 16

how many mitochondria is in each cell

Answer 16

the number of mitochondria in different cell types varies, the more active the cell is the greater number of mitochondria in that cell

Question 17

what is the endoplasmic reticulum

Answer 17

it is an interconnected system of membrane-enclosed flattened channels

Question 18

what is the difference between the rough ER and the smooth ER

Answer 18

rough ER has ribosomes attached to the outer surface whereas the smooth ER does not have any attached ribosomes. the rough and smooth ER are seperate networks of chandelles are are not physically connected

Question 19

what is the job of the rough and smooth ER

Answer 19

they are both involved in transporting different materials within cells

Question 20

what jobs does the rough ER specifically do

Answer 20

it is involved in transporting some of the proteins to various sites within a cell. this transportation is internal and the rough ER also modifies proteins

Question 21

what does the smooth ER specifically do

Answer 21

it is involved in the manufacture of substances, detoxifying harmful products and the storage and release of substances. lipid synthesis and storage is also done by the smooth ER

Question 22

what is the difference between the nucleus and nucleolus

Answer 22

nucleus - enclosed in membrane, contains dna, controls gene expression

nucleolus - not enclosed in membrane, contains ribosomal rna , produces rna