Organelles found in an animal cell - St John Fisher ... · Organelles found in an animal cell. Organelles found in a plant cell. Prokaryotic cell –no membrane bound organelles.

Organelles found in an animal cell

Organelles found in a plant cell

Prokaryotic cell – no membrane bound organelles

The nuclear

envelope

A double membrane that surrounds the nucleus. It controls the entry and exit of materials. Its outer membrane is continuous with the endoplasmic reticulum.

Nuclear pores

Allow the passage of large molecules such as messenger RNA

Nucleoplasm

The granular jelly-like material that makes up the bulk of the nucleus.

Chromatin

This is the DNA found within the nucleoplasm.

The nucleolus

A small spherical body within the nucleoplasm. It manufactures ribosomes and ribosomal RNA.

The functions of the nucleus

Involved in the production of mRNA and hence protein synthesis.

Retains genetic information in the form of DNA and

chromosomes

The mitochondrion (mitochondria)

A double membrane surrounds the organelle, the outer one controls the entry and exit of material. The inner membrane is folded to form extensions known as

cristae.

Cristae are folds of the inner membrane which increase the surface area for respiration.

The matrixis the semi rigid material containing proteins, lipids, and traces of DNA.

Mitochondria are the site of respiration, this forms ATP, (an energy carrying molecule).

Lysosomes

Lysosomes are vesicles containing digestive enzymes, formed by the Golgi apparatus.

Functions of lysosomes

Break down material ingested by phagocytic cells.

Release enzymes to the outside of the cell

(exocytosis)

Digest worn out organelles

Completely break down cells after they have died (autolysis)

Ribosomes

Ribosomes have two sub units -one large and one

small.

Ribosomes are where protein synthesis happens.

There are two types of ribosomes, 80S and 70S.

80S found in eukaryotic cells – 25nm in diameter

70S found in prokaryotic cells, mitochondria and chloroplasts they are slightly smaller

Endoplasmic reticulum

• The ER is a system of sheet-like membranes that spread throughout the cytoplasm.

• It is continuous with the outer nuclear membrane.

• There are two types of ER.

Rough endoplasmic reticulum

Rough ER (RER) has ribosomes present on the outer surfaces of the membranes. Its function is to:• Provide a large surface area for the synthesis of

proteins and glycoproteins• Provide a pathway for the transport of materials,

especially proteins throughout the cell

Smooth endoplasmic reticulum (SER)

Smooth ER (SER)

Lacks ribosomes on its surface and is more tubular in appearance. Its functions are to:

• Synthesise, store and transport lipids and carbohydrates.

Golgi apparatus

(Golgi body)

Functions of the Golgi body

Add carbohydrates to proteins to form glycoproteins

Produce secretory enzymes

Secrete carbohydrates e.g. those used to form the cell

wall in plants

Transport, modify and store lipids

Form lysosomes

VesiclesVesicles are sacs of membrane that bud off of the endomembrane system. They transport molecules such as proteins, large molecules that cannot pass through membranes, chemicals, and wastes. Vesicles are constant-forming structures that are made by the Golgi apparatus, the endoplasmic reticulum, and parts of the plasma membrane.

Chloroplasts

• Where photosynthesis happens

• Double membrane

• Grana – stacks of thylakoids – where chlorophyll is found (1st

stage of photosynthesis).

• Stroma – fluid filled (2nd stage of photosynthesis)

Vacuoles

Vacuoles

Vacuoles are storage bubbles found in cells. They are found in both animal and plant cells but are much larger in plant cells. Vacuoles might store food or any variety of nutrients a cell might need to survive. They can even store waste products so the rest of the cell is protected from contamination.

Cell wallThe cell wall is a tough, rigid layer that surrounds some types of cells. A cell wall is a characteristic feature of plant cells, bacteria and fungi.

Plant cell wall

It is not a part of the cell itself, but instead serves as protection and support to the cell. Cell walls are made of a substance called cellulose which is very light and causes the wall to become rigid.Function: The cell wall is not only used for support, but it gives the cell its shape which, overall, gives the plant itself its shape. When a plant gets water, the cells swell and push against the cell walls causing the plant not to droop.

Bacteria

Bacterial cells are prokaryotic – they do not have a nucleus.

They have a number of structures that are not found animal or plant cells.

These include ………….

Flagella (sing.flagellum)

Used for locomotion

Nucleoid

The nucleoid (meaning nucleus-like) is an irregularly shaped region within the cell of a prokaryote that contains all or most of the genetic material. In contrast to the nucleus of a eukaryotic cell, it is not surrounded by a nuclear membrane.

PlasmidA small circular piece of DNA which is separate from the main DNA of the bacterium. It may carry other genes such as those for antibiotic resistance

Mesosome

An invagination (folding in) of the membrane. It may carry out functions such as those involved in DNA replication and cell replication.

PiliPili are hollow, hairlike structures made of protein which allow bacteria to attach to other cells. A specialized pilus, the sex pilus, allows the transfer of plasmid DNA from one bacterial cell to another (sing., pilus).

Slime capsule

A layer around some bacteria that help them to stick to surfaces and avoid being killed by a host’s immune defences.