Eukaryotic cells

What is the structure of cell-surface membrane?

Structure: membrane found on surface on animal cells and inside the cell wall of other cells, it’s made of phospholipids and proteins.

What is the function of cell-surface membrane?

Function: regulates the movement of substances into and out of the cell. It also has receptor molecules on it, which allow it to respond to chemicals like hormones.

What is the structure of the nucleus?

Structure: A large organelle surrounded by a nuclear envelope (double membrane) which contains many pores and chromatin. The nucleus contains chromosomes(made from protein-bound linear DNA) and a nucleolus.

What is the function of the nucleus?

Function: nucleus control’s the cells activities (controlling transcription of DNA). DNA contains instructions to make proteins. Pores allow substances to move between the nucleus and cytoplasm. Nucleolus makes ribosomes.

What does the nucleolus do?

It produces and assembles the cell’s ribosomes, it is where rRNA genes are transcribed.

What does chromatin do?

It packages long DNA molecules into more compact and denser structures. Also the mechanism controlling how the genome is read out from cell to cell.

What do nuclear pores do?

It is the only channel to travel between nucleus and cytoplasm, allows small molecules(mRNA) and ions to freely pass or diffuse into/out of the nucleus.

What is the structure of the mitochondrion?

Structure: usually oval-shaped. They have a double membrane - the inner one is folded to form structures called cristae. Inside the mitochondrion is the matrix, it contains enzymes involved in respiration.

What is the function of mitochondrion?

Function: the site of aerobic respiration, where ATP is produced. They’re found in large numbers in cells that are very active and require lots of energy.

What is the function of cristae?

It increases the capacity of the mitochondrion to synthesise ATP, to allow a much greater amount of electron transport chain enzymes and ATP synthase to be packed in. Large surface area.

What is the structure of chloroplasts?

Structure: A small and flattened structure found in plant and algal cells. It is surrounded by a double membrane, and also has membranes inside called thylakoids. These are stacked up in some parts of the chloroplast to form grana(granum). Grana are linked together by lamellae(lamella) - thin and flat pieces of thylakoids.

What is the function of chloroplasts?

Function: The site where photosynthesis takes place. Some parts of photosynthesis happen in the grana, and other parts happen in the stroma(thick fluid).

What is the structure of the Golgi apparatus?

Structure: A group of fluid-filled membrane-bound flattened sacs. You can see vesicles at the edges of sacs.

What is the function of golgi apparatus?

Function: it processes and packages new lipids and proteins. It also makes lysosomes.

What is the structure of golgi vesicle?

Structure: small fluid-filled sac in the cytoplasm, it is surrounded by a membrane and produced by golgi apparatus.

What is the function of golgi vesicle?

Function: it stores lipids and proteins made by the Golgi apparatus and transports them out of the cell through exocytosis.

What is the structure of lysosome?

Structure: it’s a round organelle surrounded by a membrane, with no clear internal structure. A type of Golgi vesicle.

What is the function of lysosome?

Function: contains digestive enzymes called lysozymes. These are kept separate from the cytoplasm by the surrounding membrane, it can be used to digest invading cells or break down worn out components of the cell.

What is the structure of ribosome?

Structure: a very small organelle that either floats free in cytoplasm or is attached to rough endoplasmic reticulum. It’s made up of proteins and RNA. It’s not surrounded by membrane.

What is the function of ribosomes?

Function: it is the site of protein synthesis.

What is the structure of rough endoplasmic reticulum(RER)?

Structure: a system of membranes enclosing a fluid-filled space. The surface is covered with ribosomes.

What is the function of rough endoplasmic reticulum?

Function: folds and processes proteins that have been made at the ribosome.

What is the structure of smooth endoplasmic reticulum(SER) ?

Structure: similar to RER, but has no ribosomes.

What is the function of SER?

Function: synthesises and processes lipids.

What is the structure of cell wall?

Structure: rigid structure that surrounds cells in plants, algae and fungi. Plants and algae have cell walls mainly made of the carbohydrate cellulose. But in fungi it’s made of chitin.

What is the function of cell wall?

Function: supports cells and prevents them from changing shape.

What is the structure of cell vacuole?

Structure: membrane-bound organelle found in cytoplasm of plant cells. It contains cell sap which is a weak solution of sugar and salts. It’s surrounding membrane is called the tonoplast.

What is the function of cell vacuole?

Function: helps to maintain pressure inside the cell and keep the cell rigid, this stops plants wilting(loss of rigidity). Also involved in isolation of unwanted chemicals inside cell.

What are centrioles?

Centrioles are paired barrel-shaped organelles located in the cytoplasm, near the nuclear envelope. Organises microtubules that serve as the cell’s skeletal system. Determines location of nucleus and creates spindle fibres for accurate separation of chromosomes during cell division. (prophase)

What’s the difference between fungi and plants?

Both are eukaryotic, but fungi does not contain chloroplasts and their cell walls are made of chitin not cellulose.

How large animal, plant and fungal cells?

10-100 micrometers.

What is in a plant’s cell wall?

Plasmodesmata - channels in the cell wall for exchanging substances.