Anatomy of the cell

Question 1

eukaryote

Answer 1

any cell or organism that possesses a clearly defined nucleus

Question 2

what do Eukaryotic cells have

Answer 2

an outer membrane, and the interior of a eukaryotic cell is composed of organelles, the cytoskeleton, and the cytosol

Question 3

what does the plasmalemma (outer membrane) do

Answer 3

Separates cytoplasm from outside environment, forming a selectively permeable barrier

Question 4

what does the phospholipid bilayer contain

Answer 4

• Hydrophilic heads at outer and inner surfaces
• Hydrophobic tails at centre
• integral proteins

Question 5

what can the phospholipid bilayer do

Answer 5

exocytose and endocytose material

Question 6

what is the cytosol

Answer 6

solution of proteins, electrolytes and carbohydrates which the cellular components are embedded

Question 7

what does the nuclear envelope do

Answer 7

enclose the nucleus

Question 8

what does the nuclear envelope contain

Answer 8

Inner and outer nuclear membrane with the perinuclear cistern in the middl

Question 9

explain why the outer nuclear membrane is outer

Answer 9

it is studded with ribosomes

Question 10

what do Nuclear pores do

Answer 10

allow the transport of molecules across the nuclear envelope

Question 11

what does the nucleus contain

Answer 11

chromosomes

Question 12

euchromatin

Answer 12

DNA is more dispersed and undergoing transcription

Question 13

heterochromatin

Answer 13

DNA highly condensed and not undergoing transcription

Question 14

what is the nucleus the site of

Answer 14

RNA synthesis

Question 15

where are ribosomes formed

Answer 15

in the nucleolus

Question 16

how are ribosomes formed

Answer 16

Small subunit binds RNA, large subunit catalyzes peptide bond formation

Question 17

rer

Answer 17

studded with ribosomes, responsible for protein synthesis and initiation of glycoprotein formation

Question 18

ser

Answer 18

involved in continuous processing of proteins from RER and lipid synthesis

Question 19

Golgi apparatus

Answer 19

Composed of a group of flattened, membrane bound cisternae

Question 20

what happens at the Golgi apparatus

Answer 20

Transport vesicles arrive at Golgi from SER; Golgi modifies and packages them

Question 21

what does the cytoskeleton consist of

Answer 21

protein filaments which allow movement of organelles and also movement of the cell itself

Question 22

microfilaments

Answer 22

composed of actin, involved in cellular movement, cytokinesis, endo and exocytosis etc., 7nm

Question 23

Intermediate filaments

Answer 23

6 proteins that bind intracellular elements together and to the plasmalemma, >10nm

Question 24

microtubules

Answer 24

composed of alpha and beta tubulin, originate from centrosome, polar, dynein and kinesin attach and move along them, 25nm

Question 25

endocytosis

Answer 25

membrane invaginates, fuses, newly made endocytic vesicle buds into cell

Question 26

exocytosis

Answer 26

works in reverse to endocytosis

Question 27

phagocytosis

Answer 27

bacteria binds to cell surface, cell engulfs it to form phagosome, binds with lysosome containing digestive enzymes

Question 28

Occluding junctions

Answer 28

link cells to form a diffusion barrier

Question 29

what are occluding junctions also known as

Answer 29

tight junctions or zonula occludens

Question 30

Anchoring junctions

Answer 30

provide mechanical strength

Question 31

Adherent junctions

Answer 31

link submembrane actin bundles of adjacent cells via cadherin molecules

Question 32

desmosomes

Answer 32

link submembrane intermediate filaments of adjacent cells

Question 33

hemidesmosomes

Answer 33

link submembrane intermediate filaments of cells to extacellular matrix through transmembrane proteins

Question 34

what is each junction

Answer 34

Each junction is a circular patch studded with pores

Question 34

Communicating junctions (gap junctions)

Answer 34

allow movement of molecules between cells