Ch 7 Cell Structure

Question 1

Protoplasm

Answer 1

All living parts of a cell
-made up of the nucleus and cytoplasm

Question 2

What parts of an animal cell can be seen under light microscope

Answer 2

Nucleus, cytoplasm, cell membrane

Question 3

What is an animal cell surrounded by

Answer 3

Cell or plasma membrane
-membrane surround the protoplasm

Question 4

Vacuoles

Answer 4

Contain fluid called cell sap ( salts, sugar, pigments )

Question 5

What do green plant cells contain

Answer 5

Chloroplasts - for photosynthesis

Question 6

What are plant cells enclosed by

Answer 6

A rigid cell wall made of cellulose
-cell membrane is found just inside cell wall

Question 7

What are phospholipid made of

Answer 7

Phosphate and lipid

Question 8

What is cell /plasma membrane composed of

Answer 8

Phospholipids (phospholipid bilayer) and proteins

Question 9

phospholipid structure

Answer 9

Have a water loving phosphate group and a water hating lipid group

-phosphates are on the surface and lipids are in the middle

Question 10

Proteins in the cell membrane

Answer 10

-completely or partially embedded in the phospholipid bilayer
-some are attached to the bilayer
-some are detachable and move throughout the bilayer

Question 11

Selectively permeable

Answer 11

Allows some allows some things to passes through but blocks/ prevents other

Question 12

Functions of membranes

Answer 12

-membranes retain cell contents
-controls what enters and leaves the cell - selectively permeable
-give some support to the cell
-recognise molecules that touch them

Question 13

Organelles

Answer 13

Structure found inside cells
-cell membrane
-nucleus
-mitochondria
-chloroplast
-ribosomes
-cell wall
-vacuole

Question 14

Nucleus

Answer 14

Control centre of the cell- controls the activity of the cell and contains DNA

Question 15

What is a nucleus surrounded by

Answer 15

A double membrane with numerous nuclear pores

Question 16

What do nucleus contain

Answer 16

Strands of DNA - arranged into chromosomes

Question 17

Do every organisms have a definite number of chromosomes

Answer 17

Yes eg humans have 46, ferns have more than 1000

Question 18

What are located on chromosomes

Answer 18

Genes

Question 19

Chromosomes (when a cell is not dividing)

Answer 19

Chromosomes are long and interwoven - chromatin (in this form)

Question 20

Nuclear pores

Answer 20

Allow mRNA in and out of the nucleus

Question 21

Nucleolus

Answer 21

Makes ribosomes and is part of the nucleus that stains darkly

Question 22

What makes up a nucleus

Answer 22

1. Double membrane
2. Nuclear pores - control movement of substances into and out of the nucleus
3. DNA - Deoxyribonucleic acid
4. Chromatin - tangle of DNA in the nucleus
5. Chromosomes- individual strands of DNA
6. Nucleolus - contains RNA, DNA, Poteins, and makes ribosomes

Question 23

Cytoplasm

Answer 23

• jelly like liquid in the cell
• small bodies called organelles are suspended in the cytoplasm

Question 24

Mitochondria

Answer 24

Supply energy to the cell - respiration

-cells with many mitochondria produce lots of energy eg muscle, liver cells
-cells with less/ few mitochondria produce less energy eg fat cells

Question 25

What surrounds a mitochondria

Answer 25

Double membrane

Question 26

How is energy released in a mitochondrion

Answer 26

Energy is released on the inner membrane and then more infoldings, the more energy can be produced.

Question 27

What does each mitochondrion have

Answer 27

A loop of DNA

Question 28

What happens if a cell rests for too long

Answer 28

Active mitochondria Converts to inactive form (less foldings) -excercise causes number of infoldings to increase again

Question 29

Chloroplasts

Answer 29

Green stuff tires in plants in which photosynthesis occurs

Question 30

What are chloroplasts surrounded by

Answer 30

Double membrane

Question 31

Chloroplasts contain

Answer 31

Membrane stacks which green pigment chlorophyll Loop of DNA

Question 32

Cell wall function

Answer 32

To support and strengthen the cell Fully permeable - all molecules can pass through cell walls

Question 33

What are cell walls made of

Answer 33

Cellulose

Question 34

Vacuoles

Answer 34

Fluid filled space bounded by membrane -fluid = cell sap = water, food, minerals, pigments

Question 35

Function of vacuole

Answer 35

-Provide structural support -storage -waste disposal -protection + growth

Question 36

Vacuoles in plant vs animal cells

Answer 36

P- large permanent C- small, temporary (if any)

Question 37

Ribosomes

Answer 37

Function: to make proteins -tiny, bead-like structures -made of RNA, protein -they combine amino acids to form proteins

Question 38

Animal cells vs plant cells

Answer 38

Animal cells: - do not have a cell wall -do not have chloroplast (chlorophyll) -do not have a large vacuole Plant cells: -have a cell wall - may have chloroplasts/ chlorophyll - have a large vacuole

Question 39

Prokaryotic cells

Answer 39

Do not have a nucleus or membrane-enclosed organelles

Question 40

Eukaryotic cells

Answer 40

Have a nucleus and organelles which are enclosed by membranes

Question 41

Describe prokaryotic cells

Answer 41

- single called - have a circular loop of DNA (not surrounded by membrane) - have small cells - don’t have membrane enclosed organelles - include bacteria

Question 42

Describe eukaryotic cells

Answer 42

- have a nucleus - may have membrane-enclosed organelles - have large cells - includes animals, plants, fungi - more advanced than prokaryotic cells