All Eukaryote Cell Organelles

What is the function of the nucleus?

is the central control center of the eukaryotic cell and is responsible for managing the cell's genetic material

What are the structures in the nucleus and what are their functions?

• Nucleoplasm- liquid inside of nucleus, contains water and dissolved solids

• DNA- nucleus contains chromatin ( material from which chromosomes are made), chromosomes are made of sections of linear DNA tightly wound around proteins called histones

• Nucleolus-site of ribosome production

• Nuclear membrane (envelope)- double membrane of phospholipid bilateral, has inner & outer nuclear membrane with inter membrane space

• Nuclear pore- allows substances to leave & enter nucleus

What is the function of the mitochondria?

It is the site of aerobic respiration and ATP production

What are the structure inside the mitochondria and what are their functions?

• Double membrane- inner and outer mitochondrial membrane with inter membrane space

• Cristae- inner membrane is folded to provide a large surface area

• Matrix- liquid containing water and solutes

• MtDNA- used to make MRNA

What is the function of the ribosomes?

Protein synthesis

What are the structures in the ribosomes and what are their functions?

• Site of Protein synthesis- translation

• Found freely in the cytoplasm of all cells or as part of the rough endoplasmic reticulum in eukaryotic cells

• Where amino acids are joined together to make the proteins primary structure from MRNA(translation)

• No membrane

• Large and small subunits- smaller in prokaryotes 70S and bigger in eukaryotes 80S

What is the function of the Rough Endoplasmic Recticulum?

• Surface covered in ribosomes

• Formed from continuous folds of membrane continuous with the nuclear envelope

• Processes proteins made by the ribosomes

• Ribosomes attached to its outer surface which join amino acids to for, the primary structure of the protein

• Site of further folding within,forming secondary and tiertiary structure

What is the function of the Smooth Endoplasmic Recticulum?

• Does not have ribosomes on the surface, its function is distinct to the RER

• Involved in the production, processing and storage of lipids, carbohydrates and steroids

What are lysosomes?

Contains enzymes such as proteases,lipases,lysozymes (hydrolytic enzymes that can break down some bacterial cell walls)to break down substances

What is the function and structure of the vacuole?

• Sac in plant cells surrounded by the tonoplast

• Vacuole contains a temporary food store made of sugars,amino acids and pigment 

• Low water potential

• Can become turgid

• Vacuoles in animal cells are not permanent and small

What is the function and structure of the Golgi Apparatus?

• Flattened sacs of membrane similar to the smooth endoplasmic reticulum

• Modifies proteins and lipids before packaging them into Golgi vesicles

• The vesicles then transport the proteins and lipids to their required destination

• Proteins that go through the Golgi apparatus are usually exported (e.g. hormones such as insulin), put into lysosomes (such as hydrolytic enzymes) or delivered to membrane-bound organelles

What is a vesicle?

Membrane-bound sac for transport and storage

• Bud off the RER and goes to Golgi and fuses with it

• Exocytosis

What is the function of the chloroplast?

Photosynthesis

What is the structure of the chloroplast?

• Larger than mitochondria, also surrounded by a double-membrane

• Membrane-bound compartments called thylakoids containing chlorophyll stack to form structures called grana

• Grana are joined together by lamellae (thin and flat thylakoid membranes)

• Chloroplasts are the site of photosynthesis:

  The light-dependent stage takes place in the thylakoids

  The light-independent stage (Calvin Cycle) takes place in the stroma

• Also contain small circular pieces of DNA and ribosomes used to synthesise proteins needed in chloroplast replication and photosynthesis

Describe the structure of plant structure.

• Cell wall-made from cellulose(Beta glucose) from micro fibrils, fibrils which make a cellulose fibre, provides strength

• strength for the cell and prevents cell lysis(bursting)by osmotic pressure (too much water influx )

• provides overall mechanical strength for the plant

• Permeable to water and molecules allowing transport.

• Space in between cell walls