Chapter 3: Cell Structure

What are the cell walls of fungal cells made up of

They are made of chitin instead of cellulose

Do fungal cells contain chloroplast

No they do not

Which cells have an identical set of organelles to Algal cells

Plant cells

What is the material the cell wall within a plant cell made of

Cellulose

What is the difference between organelles within prokaryotes and Eukaryotes

Organelles within a eukaryotic cell are enveloped within a membrane whereas in prokaryotic cells they are not

What is the plasma membrane made from

Phospholipid belayer and a phosphate containing group

What type of DNA is found within bacterial cells

Circular DNA

What type of DNA is found within Eukaryotic cells

Linear DNA

What is the name of the membrane that the nucleus is enveloped in

The nuclear envelope

Describe the structure of the mitochondrion

Double membrane made up of the inner and outer membrane

Cristae are extensions of the inner membrane

The matrix makes up the rest of the mitochondrion

Nucleus (Structure)

Nuclear envelope

Nuclear pores

Nuecleoplasm

Nucleolus

Chromosomes

What is the purpose of the nuclear envelope

Double membrane

The outer membrane is continuous with the endoplasmic reticulum

Contains reactions that take place within the nucleus

Controls the movement of objects into and out of the nucleus

What is the purpose of the nuclear pores

Allows the passage of large molecules (mRNA)

40-100μm in diameter

What is the purpose of the nucleoplasm

A granular jelly like material

Makes up the bulk of the nucleus

What is the purpose of the nucleolus

Manufactures ribosomal RNA and assembles ribosomes

Mitochondrion (Structure)

Cristae

Matrix

Double membrane

What is the purpose of the Cristae

Extensions of the inner membrane

Provides a large surface area for the attachment of enzyme and other proteins involved with respiration

What is the purpose of the matrix

Makes up the remainder of the mitochondrion

Contains ribosomes, proteins, lipids and DNA which allow the mitochondria to control the production of their own proteins

What is the purpose of the double membrane

Controls the entry and exit of material

The inner membrane folds to form extensions (Cristae)

Chloroplast (Structure)

Chloroplast envelope

Grana

Thylakoids

Stroma

The chloroplast envelope

A double plasma membrane

Surrounds the organelle

Highly selective of what it allows to enter and leave the chloroplast

What is the purpose of the Stroma

It is where the second stage of Photosynthesis takes place, Within the stroma there are a number of other structures such as starch grains

What is the purpose of the thylakoids

contains Chlorophyll (photosynthetic pigment

What is the purpose of the grana

Where the first stage of photosynthesis takes place, Absorbs light

Grana (Structure)

Stacks of up to 100 Thylakoids

Thylakoids (Structure)

disks where the chlorophyll is stored

Arranged in stacks of up to 100 disks

Where the first stage of photosynthesis takes place (light absorption)

Stroma (Structure)

A fluid filled matrix

Where the second stage of photosynthesis takes place

There are other structures such as starch grains within the stroma

Nucleus (Purpose)

Found only in Eukaryotic cells, Carries genetic information/hereditary material (chromosomes), controls the cells activities.

Between 10-20μm in diameter

Mitochondrion (Purpose)

The site of aerobic respiration, responsible for the production of ATP.

It produces ATP from respiratory substances such as glucose

Chloroplast (Purpose)

Responsible for photosynthesis within plant cells.

They are adapted to their function through:

The large surface area of the general membrane, allowing for the attachment of chlorophyll

The fluid of the stroma contains the necessary enzymes needed to make sugars within the second stage of mitosis

They contain both DNA and Ribosomes so they are able to quickly manufacture the proteins required for photosynthesis

Golgi Apparatus (Purpose)

The Golgi modifies the proteins and lipids which are passed through by adding non-protein components (e.g carbohydrates)

Labels the proteins and lipids so that they are able to be appropriately sorted

Summary:

It adds carbohydrates to proteins to form glycoproteins

produces secretory enzymes

Secretes carbohydrates

Processes and packages new lipids

Golgi Vesicle (Purpose)

Store lipids and proteins made by the Golgi apparatus

Transports the proteins and lipids out of the cell

Lysosome (Purpose)

Hydrolyse material ingested by phagocytic cells

Release enzymes to the outside of the cell (exocytosis) in order to destroy material around the cell

Digest worn out organelles To recycle the chemicals the organelles were made of

To completely break down cell after they have died (autolysis)

Rough endoplasmic reticulum (Purpose)

To provide. Large surface area for the synthesis of proteins and glycoproteins

To provide a pathway for the transport of materials (especially proteins)

Smooth endoplasmic reticulum (Purpose)

To synthesise store and transport lipids as well a carbohydrates

Ribosomes (purpose)

To synthesise protein

Cell Wall (Purpose)

To provide mechanical strength to the cell, prevents the cell from bursting under the pressure created by the osmotic entry of water

To provide structure and strength to the plant as a whole

Vacuole (Purpose)

Supports the cells by making them turgid

The sugars and amino acids stored inside may be used as a temporary food source

The pigments stored may attract pollinating animals/insects

Cell membrane (Purpose)

To control the movements of objects into and out of the cell

The surface of the membrane has receptor cells which allow it to detect the presence of chemicals such as hormones

What are the names of the stages if the interphase

G1, S, G2

What are the four stages of mitosis

Prophase

Metaphase

Anaphase

Telophase

What happens during the prophase

DNA in the nucleus begins to condense

Chromosomes become more visible in the light microscope

Nuclear membrane dissolves

What happens during metaphase?

Chromosomes align along the middle of the cell

The line that forms is referred to as the metaphase plate

Spindles attach at the centromeres

Chromosomes begin to move

Nuclear envelope has disappeared

What Happens during anaphase?

Paired chromosomes separate and the centromeres

Move to opposite poles of the cell as the spindle fibres contract

What happens during the telophase

New membranes form around the daughter nuclei

Chromosomes disperse and are no longer visible under the light microscope

What is cytokinesis?

The completion of division

What stage of Mitosis does B represent, explain your answer

Prophase, the chromosomes are more visible

What stage if mitosis is D, Explain your answer

Metaphase, the chromosomes are aligned in the middle of the cell, they are on the metaphase plate

What stage of mitosis is E, explain your answer

Anaphase, being pulled to polar ends of the cell