Anatomy of the Cell 🗸

Question 1

Eukaryote

Answer 1

any cell or organism that possesses a clearly defined nucleus

Question 2

main features of an eukaryotic cell

Answer 2

outer membrane, organelles, cytoskeleton and cytosol

Question 3

plasmalemma (outer membrane)

Answer 3

separates cytoplasm from outside environment, forms a selectively permeable barrier with integral proteins
can exocytose and endocytose material

Question 4

what is the plasmalemma made from

Answer 4

phospholipid bilayer (hydrophobic tails and hydrophilic heads)

Question 5

cytosol

Answer 5

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

Question 6

nuclear envelop

Answer 6

encloses nucleus
has an inner and outer nuclear membrane with the perinuclear cistern in the middle
has nuclear pores

Question 7

nuclear pores

Answer 7

allows for the transport of molecules across the nuclear envelope

Question 8

nucleus

Answer 8

contains chromosomes
site of RNA synthesis

Question 9

types of chromosomes found in the nucleus

Answer 9

euchromatin
heterochromatin

Question 10

euchromatin

Answer 10

DNA is more dispersed and undergoing transcription

Question 11

heterochromatin

Answer 11

DNA is highly condensed and not undergoing transcription

Question 12

which RNA is synthesised in the nucleus

Answer 12

mRNA and tRNA in the nucleus
rRNA in the nucleolus

Question 13

Ribosomes

Answer 13

formed in the nucelus
small subunits bind RNA
large subunits catalyse peptide bond formation

Question 14

two types of endoplasmic reticulum

Answer 14

rough (RER) and smooth (SER)

Question 15

RER

Answer 15

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

Question 16

SER

Answer 16

involved in continuous processing of proteins from RER and lipid synthesis

Question 17

golgi apparatus

Answer 17

made of a group of flattened, membrane bound cisternae
transport vesicles arrive from SER, golgi modifies and packages them

Question 18

Cytoskeleton

Answer 18

consists of microfilaments, intermediate filaments and microtubules
allows movement of organelles and of the cell

Question 19

microfilaments

Answer 19

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

Question 20

intermediate filaments

Answer 20

> 10nm
6 proteins that bind intracellular elements to each other and the plasmalemma

Question 21

microtubules

Answer 21

25nm
composed of ⍺ and β tubulins which originate from the centrosome and are polar
dynein and kinesin attach and move them along

Question 22

endocytosis

Answer 22

membrane invaginates then fuses
the newly made endocytic vesicle will bud into the cell (often receptor mediated)

Question 23

Exocytosis

Answer 23

the reversal to endocytosis, the exocytic vesicle will leave the cell

Question 24

phagocytosis

Answer 24

bacteria binds to cell surface
cell engulfs it to form a phagosome
binds with lysosome containing digestive enzyme

Question 25

Three main types of intracellular junctions

Answer 25

Occluding
Anchoring
Communicating (gap junctions)

Question 26

Three types of Anchoring junctions

Answer 26

Adherent
desmosomes
hemidesmosomes

Question 27

Occluding junction

Answer 27

link cells together to form diffusion barrier
may be referred to as tight junctions or zonula occludens

Question 28

Anchoring junction

Answer 28

provide mechanical support

Question 29

Adherent Junction (Anchoring junction)

Answer 29

link submembrane actin bundles of adjacent cells via cadherin molecules

Question 30

desmosomes (Anchoring junction)

Answer 30

link submembrane intermediate filaments of adjacent cells

Question 31

hemidesmosomes (Anchoring junction)

Answer 31

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

Question 32

Communicating Junctions (gap junctions)

Answer 32

allows movement of molecules between cells
each junction is a circular path studded with pores