Cell Structure

Features

• Made up of lipids, proteins, glycolipids and glycoproteins
• Found on the surface of animal cells
• Just under the cell wall in plant cells and prokaryotic cells

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

Features

• A large organelle surrounded by a nuclear envelope (double membrane), which contains many pores
• Contains chromosomes (made up from protein-bound linear DNA) and one or more structures (an area of denser genetic material) called a nuceolus (or nucleoli)

Function

• Controls the transcription of DNA
• DNA contains instructions to make proteins
• The pores allow substances (like RNA) to move between the nucleus and the cytoplasm
• The nucleolus makes ribosomes

Features

• Usually oval shaped (under a microscope this can change)
• They have a double membrane
• The inner membrane is folded to form structures called the cristae. Inside this is the matrix, which contains enzymes involved in respiration

Function

• This is the site of aerobic respiration, where ATP is produced
• Found in large numbers in cells that require a lot of energy

Features

• A small, flattened structure found in plant and algal cells
• Surrounded by a double membrane
• Contains membranes called thylakoid membranes. These are stacked up in some parts of the chloroplast to form grana. Grana are linkec together by lamellae - thin flat pieces of thylakoid membrane

Function

• The site where photosynthesis takes place
• Some parts of photosynthesis take place in the grana, others happen in the stroma (the thick fluid found in chloroplasts)

Features

• A group of fluid-filled, membrane-bound flattened sacs
• Vesicles are often seen at the edges of the sacs

Functions

• Processes and packages new lipids and proteins
• Makes lysosomes

Features

• A small, fluid-filled sac in the cytoplasm, surrounded by a membrane and produced by the Golgi apparatus

Function

• Stores lipids and proteins made by the Golgi apparatus and transports them out of the cell

Features

• A round organelle surrounded by a membrane, with no clear internal structure
• A type of Golgi vesicle

Function

• Contains digestive enzymes called lysozymes
• Keeps lysozymes separate from cytoplasm as it could cause autolysis
• Can be used to digest invading cells or break down worn out components of the cell

Features

• A very small organelle that either floats free in the cytoplasm or is attached to the rough endoplasmic reticulum
• Made up of proteins and RNA
• No membrane
• Has a small (light) subunit and a large (heavy) subunit

Function

• The site where proteins are made

Features

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

Function

• Folds and processes proteins that have been made at the ribosomes

Features

• A system of membranes enclosing a fluid-filled space
• No ribosomes

Functions

• Synthesises and processes lipids

Features

• A rigid structure that surrounds cells in plants, algae and fungi (and some prokaryotic cells)
• In plants and algae it's made mainly of cellulose
• In fungi, it is made up of chitin

Function

• Supports cells and prevents them from changing shape

Features

• A membrane-bound organelle found in the cytoplasm of plant cells
• Contains cell-sap - a weak solution of sugar and salts
• Surrounding membrane is called the tonoplast

Function

• Helps maintain pressure inside the cell and keeps the cell rigid
• Stops plant wilting
• Involved in the isolation of unwanted inside the cell