Cell structure

Question 1

Eukaryotic Cell

Answer 1

A cell that contains a nucleus and other membrane-bound organelles

Question 2

Ultrastructure

Answer 2

The structural features that are seen in a cell under an electron microscope

Question 3

Nucleus

Answer 3

Contains all DNA in form of chromosomes that code for proteins.
Controls all metabolic processes in the cell.
Has an envelope that controls substances that move across nucleus.

Question 4

Nucleolus

Answer 4

Contains proteins and RNA that are used to synthesize ribosomes.

Question 5

Mitochondria

Answer 5

Site of aerobic respiration and production of ATP.
Double membrane- Cristae and fluid Matrix
Contains mitochondrial DNA mtDNA

Question 6

Vesicles

Answer 6

Membranous sacs that have storage and transport roles.

Contain fluid

Question 7

Lysosomes

Answer 7

Vesicles that contain hydrolytic enzymes.

Tasked with breaking down waste materials and pathogens.

Question 8

RER

Answer 8

It Has ribosomes bound to the surface

Responsible for synthesis and transport of proteins

Question 9

SER

Answer 9

Responsible for lipid and carbohydrate synthesis, and storage.

Question 10

Golgi body

Answer 10

Contains compact structure formed of cisternae

Modifies and packages proteins into vesicles.

Question 11

Ribosomes

Answer 11

80s
Constructed of RNA
Site of protein synthesis

Question 12

Cell Surface Membrane

Answer 12

Partially permeable

Controls which substances enter and exit cell

Question 13

Cell wall

Answer 13

Made of cellulose.
Rigid structure and high tensile strength
Freely permeable
Supports individual cells.

Question 14

Cilia

Answer 14

Hair like extensions
Mobile/Stationary cilia.
Stationary important for sensory
Mobile beat in rhythm: causing movement of substances eg mucus.
9+2 arrangement two central + nine outer microtubules

Question 15

Intermediate Fibres

Answer 15

Give mechanical strength to cells and help maintain integrity.

Question 16

Cell Movement

Answer 16

Actin filament changes with the addition and removal of monomer subunits.
Subunits can only be added in the correct orientation.
Change shape at - end but not + end so faster rate at + so moves.

Question 17

Treadmilling

Answer 17

Due to the difference in the rate of addition at either end, at certain concentrations, some subunits will be added at one end and removed in another.

Question 18

Centrioles

Answer 18

Composed of microtubules.

Two centrioles form a centrosome - involved in assembly and organisation of spindle fibres in cell division.

Question 19

Chloroplasts

Answer 19

An organelle is responsible for photosynthesis in plant cells.
Double membrane
The fluid inside called the stroma.
The network of membranes which form flattened sacs called thylakoids, many stacked called grana. which contain chlorophyll
Grana joined by lamellae

Question 20

Protein Production Process

Answer 20

1)Proteins synthesized in ribosomes of RER.
2)Passed into cisternae of RER and packaged into transport vesicles
3)Vesicles move towards the Golgi body via cytoskeleton and fuse with the cis face of the Golgi body and enter.
4)Proteins are structurally modified and re-packaged into secretory vesicles from the trans face.
5)Secretory vesicles carry proteins that are being expelled from the cell at the CSF membrane.
5)Exocytosis occurs.
Or stored in lysosomes as hydrolytic enzymes.

Question 21

Prokaryotic Cell

Answer 21

Cells with no membrane-bound nucleus or organelles.

Question 22

Prok. Cell Wall

Answer 22

Rigid outer covering made of peptidoglycan

Question 23

Prok. Ribosomes

Answer 23

70s, slightly smaller. Only freely suspended

Question 24

Bacterial Flagellum

Answer 24

a tail-like structure which rotates to move the cell
no 9+2
energy from chemiosmosis
attached by the basal body and rotated by a molecular motor.

Question 25

Plasmid

Answer 25

A circular piece of DNA | Allows for sharing of genes between microorganisms.

Question 26

Chromosome (Nucleotide)

Answer 26

Singular circular chromosome- supercoiled to make it compact. Grouped into operons which are on or off.

Question 27

Pili

Answer 27

Hair-like structures which attach to other bacterial cells

Question 28

Slime capsule

Answer 28

The protective slimy layer that helps the cell to | retain moisture and adhere to surfaces

Question 29

Endosymbiotic Theory

Answer 29

The theory that mitochondria and chloroplasts and other eukaryotic organelles were formerly free-living bacteria (prokaryotes). These prokaryotes were taken inside as an endosymbiont.

Question 30

Endosymbiont

Answer 30

An organism that lives within the body or cells of another organism.