What is a eukaryotic cell?
Eukaryotic cells make up multicellular organisms, such as animals, plants and fungi. There structure is much more complex
What are the cell components of a eukaryotic animal cell?
*Rough endoplasmic reticulum
*smooth endoplasmic reticulum
*Flagellla and cilia
What does the nucleus contain?
What does the DNA do in the Nucleus?
The DNA directs the synthesis of all proteins required by the cell. The DNA controls the metabolic activities of the cell (as many of the proteins and enzymes are used for the metabolic process).
What does the Nucleolus produce?
What is the Nucleolus made from?
The Nucleolus is made from proteins and RNA
What is RNA used for in the Nucleolus?
RNA is used for to produce ribosomal which is then combined with proteins to form the ribosomes necessary for protein synthesis.
Describe the structure of Mitochondria
The inner membrane is folded to form structures called cristae. Cristae contain enzymes used in aerobic respiration. The flued interior is called the matrix. Mitochondria contain a small amount of DNA called mitochondrial DNA. Mitochondria can produce there own enzymes and reproduce themselves.
What do the Mitochondria do?
Mitochondria carry out cellular respiration. The energy stored in the bonds of complex, organic molecules is made available for the cell to use by the production of molecular ATP.
What is the amount of Mitochondria in a cell determined by?
The amount of energy the cell needs 🏃🏻
What are vesicles?
Vesicles are membranous sacs that store and transport material inside cells
What are vesicles made of?
Vesicles are made from a single membrane with fluid inside (very simple organelle)
What are Lysomes?
Lysomes are specialised forms of Vesicles that contain hydrolytic enzymes.
What do Lysomes do?
Lysomes break down waste materials in cells, including old organelles. They break down pathogens ingested by phagocytise cells. They also play a role in programmed cell death or apoptosis.
What is the cytoskeleton?
What does the cytoskeleton do?
The cytoskeleton holds organelles in place, is responsible for the stability of the cell. It also controls the cells movement, and the movement of organelles within the cell. It also determines the shape of the cell.
What are the three main components of the cytoskeleton?
- Intermediate fibres
What are microfilaments?
Fibres formed from the protein actin that are capable of contraction. They are responsible for cell movement (via treadmilling) and also cell contraction during cytokinesis; the process were the cytoplasm of a single eukaryotic cell devices to form two daughter cells.
What are microtubules?
- The shape of the cell is determined when globular tubulin proteins polymerise to form tubes that are used to form a scaffold like structure.
- they also act like tracks for the movement of organelles around the cell.
- spindle fibres are composed of microtubules, and physically split chromosomes during cell division.
What are intermediate fibres?
Intermediate fibres give mechanical strength to cells and help to maintain their integrity (true form)
What are Centrioles made from?
Centrioles are composed of microtubules
What are Centrioles?
Centrioles are a component of the cytoskeleton present in most eukaryotic cells (but not flowering plants or most fungi).
Drawer and label a eukaryotic cell
Check page 27
Were is the Nuceolus located?
Within the nucleus
Where are microfilaments mainly found?
Outside the cell.
Were are microtubules located?
Mainly near the edge of the cell wall.
What do centrioles do?
Two centrioles form a centrosome, which is involved in the assembly and organisation of spindle fibres during cell devision. Centrioles are thought to play a role in the positioning of flagella and cilia.
Were are the flagella or cilia located?
What are flagella used for?
They are used primarily to enable a cells motility. In some cells they are used as a sensory organelle detecting chemical changes in the cell’s environement.
What is the function for stationary cilia?
Stationary cilia have an important function in sensory organs (such as the nose).
where are stationary cilia located?
Stationary cilia are present on the surface of many cells
What is the function of mobile cilia?
Moblile cilia beat in a rythmic manner, creating a current, and and cause fluids or objects adjacent to the cell to move.
Name two places were mobile cilia are found in the body
- They are found in the trachea to move mucus away from the lungs.
- They are foud in the fallopian tubes to move egg cells from the ovary to the uterus.
Describe the anatomy of a cilium
Each cilium contains two central microtubules that are surrounded by nine pairs of microtubules. This is known as the 9+2 arrangement.
How does the anatomy of the cilia allow for a beating motion?
Pairs of parallel microtubules slide over each other causing the cilia to move in a beating motion
Name the two endoplasmic reticulum
- Smooth endoplasmic reticulum
- Rough endoplasmic reticulum
What is the function of the smooth ER?
It is responsible for lipid and carbohydrate synthesis and storage.
Describe the structure and the function of the rough ER
Has ribosomes bound to the surface and is responsible for the synthesis and transport of proteins.
Describe the structure of a ribosome
Ribsosomes are not surrounded by a membrane. They are constructed of RNA molecules made in the nucleolus of the cell.
Ribosomes are the site of…
Describe the structure of the golgi apparatus
It is a compact structure formed of cristernae.
What does the golgi apparatus do?
Modifies protiens and packages them into vesicles.
Describe the process of protein production
- Proteins are synthesised on the ribosomes bound to the endoplasmic reticulum.
- They then pass through the cristernea and are packaged into transport vesicles.
- These vesicles then move to the golgi apparatus via the transport function of the cytoskeleton.
- The vesicles fuse with the cis face of the golgi apparatus and the protein enter.
- The proteins are structually modified before leaving the golgi apparatus in vesicles from its trans face.
- Secretory vesicles carrying these protiens then move towards the cell membrane
- They fuse with the cell-surface membrane, releasing there contents by exocytosis.
Draw a diagram for protein production
Check page 31