Structure of eukaryotic cells

Eukaryotes

Multicellular organisms made up of eukaryotic cells like animals, plants, fungi, and protists.

Plants and animal cells are eukaryotic cells because they contain a membrane-bound nucleus and membrane-bound organelles such as mitochondria

Prokaryotes

Single-celled organisms made up of prokaryotic cells like bacteria.

Prokaryotic cells don't have a nucleus

What are the organelles in a eukaryotic cells (plant and animals)

Cell surface membrane

Mitochondria

Ribosomes

Nucleus

Nucleolus

Lysosomes

Smooth endoplasmic reticulum

Rough endoplasmic reticulum

Golgi apparatus and Golgi vesicles

What are the organelles only found in plants?

Cellulose cell wall with plasmodesmata

Chloroplasts

Permanent vacuole

Cell surface membrane structure

Membrane found on the surface of animal cells and just inside the cell wall of other cells.

Mainly made of phospholipids and proteins

Cell surface membrane function

Regulates the movement of substances into and out of the cell.

Has receptor molecules on it, which allow it to respond to chemicals like hormones

Nucleus structure

The largest organelle and is surrounded by a nuclear envelope (double membrane), which contains many pores

Contains genetic information in the form of chromosomes (the DNA is in the form of linear chromosomes, made of DNA wound around proteins)

Contains the nucleolus which is a dark, granular area inside the nucleus that contains DNA and proteins

Nucelus function

Contains DNA, which holds the genetic information necessary to control the cell

The nucleolus synthesises ribosomes

Substances can enter or leave the nucleus via the nuclear pores which allows exchange between nucleus and cytoplasm

Nucleolus

A dark, granular area inside the nucleus that contains DNA and proteins.

Mitochondria structure

Bean-shaped organelles that have a double membrane around them

The inner membrane one is folded to form structures called cristae

Inside is the matrix which contains enzymes involved in respiration

Mitochondria function

The site of aerobic respiration where ATP is produced. They're found in large numbers in cells that are very active and require a lot of energy

Ribosomes structure

A very small organelle found in the cytoplasm or attached to rough endoplasmic reticulum

It is made up of proteins and RNA

Consist of a large and a small subunit

Not surrounded by a membrane

Ribosomes function

Site of protein synthesis- involved in the process of translation

Golgi apparatus structure

Contain fluid-filled, membrane bound flattened sacs known as cisternae

Vesicles are constantly pinched off the ends of the sacs

Golgi apparatus function

Modify proteins made at the rER, for example adding carbohydrates to form glycoproteins

Processes and packages lipids and proteins, which is carried out by the cisternae

Stores and transports lipids and proteins, which is carried out by the vesicles

Specialised vesicles also synthesise lysosomes

Rough endoplasmic reticulum (rER) structure

Layers of membranes that form flattened, interconnected tubes through the cytoplasm

The outer face is covered in ribosomes

Rough endoplasmic reticulum (rER) function

Synthesise proteins and transport them to the golgi apparatus

Smooth endoplasmic reticulum (sER) structure

Similar to rER but the cavities are more tubular and the membranes do not have ribosomes

Smooth endoplasmic reticulum (sER) function

Synthesis, storage and transport of lipids and carbohydrates

Lysosomes structure

Membrane bound vesicles containing hydrolytic enzymes (lysozymes) produced by the Golgi apparatus

The membrane is to keep enzymes separate from the cytoplasm of the cell

lysosomes function

The enzymes are used to digest pathogens and break down waste material

Cell wall structure

In plants, the cell wall is made of cellulose fibres and surrounds the cell surface membrane

Algal cell walls are typically made of glycoproteins and polysaccharides

Fungal cell walls are usually made of the carbohydrate chitin

Contains channels (gaps) known as plasmodesmata

cell wall function

The cell wall surrounds the cell membrane and stops the cell bursting when it takes in water by osmosis

Plasmodesmata connects neighbouring cells allowing exchange of substances between cells

Contents of the cell press against the cell wall to make it rigid

Chloroplasts function

Contain fluid-filled sacs known as thylakoids which are stacked up to form grana

Surrounded by a double membrane, enclosing a fluid known as stroma

Contain their own DNA and ribosomes

chloroplasts function

Site of photosynthesis, some parts of photosynthesis happen in the grana and other parts happen in the stroma

Permanent Vacuole structure

A membrane bound organelle found in the cytoplasm of plant cells.

It contains cell sap and the surrounding membrane is known as tonoplast

Permanent vacuole function

Helps to maintain pressure inside the cell keeping it rigid/turgid which stops plants wilting

Cristae

Folded structures formed by the inner membrane of mitochondria.

Matrix

Inside the mitochondria, containing enzymes involved in respiration.

Cisternae

Fluid-filled, membrane-bound flattened sacs in the Golgi apparatus.

Plasmodesmata

Channels that connect neighboring plant cells allowing exchange of substances.

Thylakoids

Fluid-filled sacs in chloroplasts that are stacked to form grana.

Tonoplast

The surrounding membrane of the permanent vacuole in plant cells.

Hydrolytic enzymes

Enzymes contained in lysosomes used to digest pathogens and break down waste material.

Glycoproteins

Proteins modified by the Golgi apparatus by adding carbohydrates.

ATP

Adenosine triphosphate, produced during aerobic respiration in mitochondria.

Cellulose

A carbohydrate that makes up the cell wall in plants.

Chitin

A carbohydrate that typically makes up the cell wall in fungi.