1.2 Cell Structure

Question 1

Nucleus

Answer 1

contains DNA coding for protein synthesis in cytoplasm and controls cell activity

Question 2

Nucleus Features

Answer 2

Nuclear envelope, Nuclear Pores, Nucleolus

Question 3

Nucleus Size

Answer 3

5µm to 10µm

Question 4

Chloroplasts

Answer 4

(ONLY IN PLANT CELLS) contains chlorophyll - site of photosynthesis

Question 5

Chloroplast Features

Answer 5

Stroma, Grana, Thylakoids, Starch Grains, 70S Ribosomes, Circular DNA

Question 6

Chloroplasts Size

Answer 6

0.5 - 2 µm wide and 10 µm in length

Question 7

Mitochondria

Answer 7

Produces ATP by aerobic respiration

Question 8

Mitochondria Features

Answer 8

Cristae, Matrix, 70S Ribosomes, Circular DNA

Question 9

Mitochondria Size

Answer 9

1 µm in length

Question 10

Protein Transport within the cell

Answer 10

1) Proteins are made by ribosomes on rough endoplasmic reticulum and are pinched off into vesicles
2) Vesicles containing the proteins fuse to the Golgi Body, where they are modified
3) Vesicles containing modified proteins break away from the Golgi Body
4) Vesicles fuse with the cell surface membrane by exocytosis, releasing protein outside the cell

Question 11

Rough Endoplasmic Reticulum Function

Answer 11

ribosome and protein synthesis

Question 12

Smooth Endoplasmic Reticulum Function

Answer 12

lacks ribosomes which synthesises lipids and steroids ie. cholesterol

Question 13

Golgi Body Function

Answer 13

glycoprotein synthesis, protein modification / packaging in vesicles for export from cell

Question 14

Lysosomes

Answer 14

Contains Hydrolytic Enzymes that digests unwanted materials and worn-out organelles

Question 15

Lysosomes Size

Answer 15

0.1-0.5 µm

Question 16

Cell Surface Membrane Function

Answer 16

controls movement of substances in and out of cell - partially permeable

Question 17

Cell Surface Membrane Thickness

Answer 17

7 nm thick

Question 18

Cell Wall Function

Answer 18

(ONLY IN PLANT CELLS) made of cellulose which supports the cell by maintaining its shape

• Keeps cell firm / prevents turgidity
• Provides mechanical strength

Question 19

Plasmosdesmata

Answer 19

(ONLY IN PLANT CELLS) microscopic channels which traverse the cell walls of plant cells and some algal cells, enabling transport and communication between them

Question 20

Large Permanent Vacuole

Answer 20

(ONLY IN PLANT CELLS) might store food or any variety of nutrients a cell might need to survive

Question 21

Tonoplast

Answer 21

The membrane surrounding the large permanent vacuole

Question 22

Centrioles

Answer 22

(ONLY IN ANIMAL CELLS) a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division.

Question 23

Centrioles Size

Answer 23

0.5 µm

Question 24

Microtubules Function

Answer 24

• Forms cytoskeleton along with thinner protein filaments

- Involved with movement of organelles via special attachment proteins

Question 25

ATP stands for

Answer 25

Adenosine triphosphate

Question 26

ATP function

Answer 26

- It is the universal energy currency of the cell | - "immediate source of energy for the cell. When ATP is broken, a small packet of energy is released

Question 27

ATP hydrolysis reaction

Answer 27

ATP + water → ADP + phosphate + energy

Question 28

Features of Prokaryotes: organelles, DNA, ribosome type, flagella, cell wall material

Answer 28

- No nucleus and double membrane-bounded organelles; mitochondria & chloroplasts - Naked / circular DNA - contains plasmids - 70S ribosomes - Flagella lacks 9+2 microtubule arrangement [single] - No ER, Golgi body and lysosomes - Cell wall made of peptidoglycan (murein)

Question 29

Features of Eukaryotes: organelles, DNA, ribosome type, flagella, cell wall material

Answer 29

- Nucleus and double membrane-bounded organelles present - Linear DNA - No plasmids - DNA associated with histone proteins - Contains ER along with Golgi body and lysosomes - 70S & 80S ribosomes - Flagella contains 9+2 microtubule arrangement - Cell wall made mostly of cellulose / chitin (fungi)

Question 30

Virus

Answer 30

an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host - DNA or RNA of Virus takes over the protein synthesising machinery of host cell and helps to make new virus particles

Question 31

Virus Features

Answer 31

- No nucleus and cytoplasm - Consists of genetic material contained within a protein coat (capsid) - made up of many individual protein molecules called ‘capsomeres’ - Symmetrical shape

Question 32

Virus Size

Answer 32

Ranges in size (20–300 nm)

Question 33

Nucleolus

Answer 33

Nucleus - Synthesises rRNA and ribosomes (1-2 µm)

Question 34

Nuclear envelope

Answer 34

Nucleus - Double membrane surrounding the nucleus

Question 35

Nuclear Pores

Answer 35

Nucleus - Allows passage of large molecules ie. mRNA and ribosomal proteins to be transmitted out of the nucleus

Question 36

Stroma

Answer 36

Chloroplast - Colorless fluid surrounding the grana within the chloroplast. enzymes necessary for light independent stage

Question 37

Grana

Answer 37

Chloroplast - made up of flattened sacs; thylakoids

Question 38

Thylakoids

Answer 38

Chloroplast - An internal system of interconnected membranes, that carry out the light reactions of photosynthesis

Question 39

Starch Grains

Answer 39

Chloroplast - Acts as temporary stores of carbohydrates produced

Question 40

Cristae

Answer 40

Mitochondria - inner membrane folded

Question 41

Matrix

Answer 41

Mitochondria - Krebs cycle & oxidative phosphorylation takes place here

Question 42

Cisternae

Answer 42

Endoplasmic Reticulum - Membranes enclose a network of tubules and flattened sacs; cisternae