Cell Part 2

Question 1

Network of tiny tubular structures scattered in the cytoplasm

Answer 1

Endoplasmic Reticulum

Question 2

Name compartments that the ER divides the intracellular space into

Answer 2

Luminal (inside ER) and Extra Luminal (cytoplasm)

Question 3

Where are RERs commonly observed

Answer 3

In cells actively involved into protein synthesis and secretion

Question 4

What is “extensive and continuous” with the outer nuclear membrane

Answer 4

RER

Question 5

What is SER famous for? Animal cells specifically?

Answer 5

Lipid synthesis. In animal cells, lipid-like steroidal hormones are synthesized.

Question 6

Camillo Golgi discovered what and when?

Answer 6

He first observed densely stained Reticular structures near the nucleus in 1898.

Question 7

Golgi bodies consist of?

Answer 7

Many flat, disc shaped sacs or cisternae of 0.5 to 1 micrometer

Question 8

Cisternae dimensions

Answer 8

0.5 to 1 micrometer

Question 9

Describe Arrangement of cisternae

Answer 9

~stacked parallel to each other
~varied number present
~concentrically arranged near the nucleus
~convex cis/forming face and concave trans/maturing face

Question 10

Cis (convex/forming) is entirely same as that/different from trans? Also, connected or disconnected?

Answer 10

Entirely different. They are interconnected but disconnected in plant cells.

Question 11

Give the principal functions of golgi

Answer 11

Packaging and delivery (intracellular targets or secreted outside)

Question 12

Why is Golgi in close association with ER

Answer 12

1) . Materials to be packaged in the form of vesicles from ER enter the CIA form and move to the maturing face
2) . Proteins synthesised in ribosomes on RER are modified in the Golgi apparatus before they are released form trans face

Question 13

Golgi is an important site of formation of

Answer 13

Glycoproteins and glycolipids

Question 14

Name the membrane bound vesicular structures formed by packaging in Golgi.

Answer 14

Lysosomes.

Question 15

Isolated lysosonal vesicles have been found to be rich in?

Answer 15

Almost all types of hydrolases (Lipases, proteases, carbohydases) optimally active at acidic pH. These enzymes are capable of digesting carbohydrates, lipids, proteins and nucleic acids.

Question 16

Define vacuole. It contains? Membrane’s purpose, nature and conc? Percentage.

Answer 16

Membrane bound space found in cytoplasm. (UPTO 90% OF THE VOLUME OF THE CELL)

Water, sap, excretory product and other materials not useful for the cell.

Tonoplast facilitates the transport of a number of ions and other materials AGAINST the concentration gradient into vacuoles, hence their concentration is significantly higher in the vacuole than in the cytoplasm (is Hypertonic)

Question 17

Contractile vacuole is found in? For?

“Contractile” extensive false feet

Answer 17

In amoeba, important for excretion.

Question 18

Protists have which vacuole? Formed how?

Answer 18

Food vacuoles, formed by engulfing the food particles.

Question 19

Mitochondria is easily visible

Answer 19

Unless specifically stained, no

Question 20

Give the diameter and length of mitochondria

Answer 20

1 to 4.1 in length

0.2 to 1.0 micrometer in diameter (avg 0.5 micrometre)

Question 21

What compartmentalisation do we see due to the two membranes of he mitochondria

Answer 21

They divide the lumen into two AQUEOUS compartments: Inner and outer.

Inner: dense homogeneous mixture called matrix

Question 22

Which membrane of the mitochondria has enzymes

Answer 22

Both have their own specific enzymes associated with mitochondria function.

Question 23

Mitochondria, site of?

Answer 23

A e r o b i c. R e s p i r a t i o n.

Question 24

Mitochondria divide by?

Answer 24

Fission

Question 25

The matrix of mitochondria contains?

Answer 25

Single circular DNA, few RNA, ribosomes and components required for proteins synthesis

Question 26

Where are plastids found? Comment on visibility. | Function? Types

Answer 26

In all plants and and euglenoids. Easily seen since they are large. They bear pigments and impart color to the plant. Chloroplast: chlorophyll+carotenoids- trap light energy for photosynthesis Chromoplast: give plant yellow, orange, red color Chloroplast: colourless plastid of different shapes and sizes with stored nutrients Amylo- starch, Elaio-fat and oils, aleuro-protein

Question 27

Carotenoid pigments are water soluble or fat soluble?

Answer 27

FAT SOLUBLE

Question 28

Chloroplast have dimensions

Answer 28

Length (5 to 10) micrometre | Width (2 to 4) micrometre

Question 29

Different shapes of chloroplasts

Answer 29

``` Lens Oval Spherical Discoid (higher plants) Ribbon like (Spirogyra) ```

Question 30

Number of chloroplasts in Chloroplast and higher plants

Answer 30

1 per cell: chlamydomonas | 20-40 per cell: mesophyll

Question 31

Which membrane is relatively less permeable?

Answer 31

The inner membrane

Question 32

Define stroma. It contains? Define grana.

Answer 32

Space limited by the inner membrane. It contains a number of organised, flattened membranous sacs called the thylakoids. Grana aka INTERGRANAL THYLAKOID: Thylakoids arranged in a stack like piles of coins

Question 33

Stroma lamellae?

Answer 33

Flat, membranous tubules which connect the thylakoids of different grana.

Question 34

Membrane of thylakoid encloses a? Thylakoid contains whaaaat?

Answer 34

Lumen. Chlorophyll pigments.

Question 35

Stroma of chloroplast contains enzymes for? It also contains?

Answer 35

Synthesis of proteins and carbohydrates. Small, ds, circular DNA and ribosomes.

Question 36

Comment on the size of chloroplastic ribosomes relative to cytoplasmic ribosomes

Answer 36

Chloroplastic ribosomes are much smaller.

Question 37

Ribosomes were discovered by? When?

Answer 37

Observed as granular structures under the e microscope by GEORGE PALADE (1953)

Question 38

70 S : svedberg's unit

Answer 38

Sedimentation coefficient, indirectly a measure of DENSITY and SIZE.

Question 39

Ribosomes are composed of?

Answer 39

Ribonucleic acid and proteins

Question 40

An elaborate network of filamentous, proteinaceous structures present in the cytoplasm? Functions

Answer 40

Cytoskeleton (eukaryotes) Mechanical support, motility, maintenance of cell shape.

Question 41

Hair like outgrowths of the cell membrane are? Describe. Compare. Do prokaryotes have them?

Answer 41

Cilia and flagella Cilia: small structures which work like oars, using the movement of either the cell or the surrounding fluid Flagella: comparatively longer, responsible for cell movement Present in prokaryotes, just structurally different.

Question 42

Describe structure of cilia and flagella

Answer 42

~Covered with plasma membrane. ~Their core is called AXONEME, which possesses a number of microtubules running parallel to the long axis ~Axoneme: 9 pairs of microtubule doublets (radially arranged, peripheral) + pair of centrally located microtubule (enclosed by a central sheath, connected by bridges) (9+2) ARRAY ~one of the tubules of each peripheral doublet is connected to the central sheath by a radial spoke (hence, nine in number and radial) ~peripheral doublets connected by linkers

Question 43

Cilia and flagella emerge from

Answer 43

Centriole like structure called BASAL BODIES.