Cell Structure

Question 1

Nucleus

Answer 1

Surrounded by double nucleus envelope with nuclear pores . Filled with nucleoplasm which contains chromatin made from DNA and proteins. Provides instructions for making proteins.

Question 2

Mitochondria

Answer 2

Double membrane, inner surface folded to form cristae gives large SA, matrix contains DNA, ribosomes and enzymes produce ATP during aerobic respiration

Question 3

Smooth endoplasmic reticulum

Answer 3

System of interconnected hollow tubes and sacs, produces fats and oils

Question 4

Rough endoplasmic reticulum

Answer 4

Interconnected system of hollowed sacs covered in ribosomes, translation takes place where peptide chains are assembled into proteins.

Question 5

Golgi apparatus

Answer 5

Flattened membrane-bound cavities called cisternae . Modifies and packages proteins, makes lysosomes.

Question 6

Lysosome

Answer 6

Vesicle made in Golgi. Contains hydrolase enzymes which catalyse hydrolysis reactions.

Question 7

Vesicles

Answer 7

Temporary structure that stores substances inside cells and transport substances in and out of cell

Question 8

Permanent vacuole

Answer 8

Formed whenseveral vesicles fuse together. Meymaintan turgor and provide structural support in animal and plant cells. In fungi, they degrade redundant organelles, have storage functions and may remove toxins.

Question 9

Chloroplast

Answer 9

Have double membrane that enclosed the stoma which surrounds thylakoid membranes which are stacked into grana. Site of photosynthesis in plants.

Question 10

Ribosomes

Answer 10

80s non-membrane bound- have small and large sub-unit, used when proteins are made in eukaryotic cells. in prokaryotic cells, 70s provide binding sites for mRNA and tRNA during protein synthesis.

Question 11

Bacterial DNA

Answer 11

A single continuous strand of DNA and located in nucleoid. Contains genetic material needed to control the normal functional cell.

Question 12

Plasmids

Answer 12

Circular double stranded extra-chromosomal DNA molecules - not essential

Question 13

Capsules

Answer 13

A type of glycocalyx (sugar coat) formed from polysaccharides and proteins. They absorb water to prevent drying out. Aid in formation of biofilms protect cell from being engulfed

Question 14

Flagella

Answer 14

Long projections from the cell surface made from flagellin, hook and protein disk. Counter-clockwise rotation so cell propels in one direction

Question 15

Pilus

Answer 15

short projections on outer surface of cell. Sex pili transfer genetic material (horizontal transfer)in pathogenic strainS of bacteria, they play a role in virulence.

Question 16

Cytoskeleton

Answer 16

Network of protein threads within cytoplasm, is dynamic. Made of 3 protein fibres: microfilaments, intermediate filaments and microtubules

Question 17

Microfilaments

Answer 17

Made from actin, involved in processes that involve movement around the cell

Question 18

Intermediate filaments.

Answer 18

Made of a variety of proteins and play structural roles

Question 19

Microtubules

Answer 19

Made from alpha and beta tubulins and have structural functions

Question 20

Centrioles

Answer 20

Small, hollow cylinders made of microtubules

Question 21

Cilia

Answer 21

Small, hair-like structures, microtubules allow them to move, movement is used by cell to move substances along the cell surface.

Question 22

Flagellum

Answer 22

Microtabules stick out from the cells surface and are surrounded by plasma membrane. Microtubules contract Tomane flagellum more and are used as outward motors to propel the cell forward.