Cell Structure Flashcards
Define the term “eukaryotic cell”
Cells with a nucleus and other membrane-bound organelles
Draw diagrams of a typical plant and animal cell, labelling the structures of the cell and annotating with their function.
Find a labelling activity online or print out a blank diagram.
Outline the structure and function of the nucleus.
Structure:
- Contains coded genetic information in the form of
DNA molecules
- Has a double membrane (nuclear envelope)
- Has pores (nuclear pores) to release RNA
- The nucleus contains chromatin which is made from DNA and proteins and often a structure called the nucleolus
Function:
- Controls cells activities and contains and instructions to make proteins
- The pores allow substances (RNA) to move between the nucleus and the cytoplasm.
- Define the term “ultrastructure”.
The ultrastructure of a cell is those features which can be seen using an electron miscroscope
Outline the structure and function of the nucleolus
- An area within the nucleus and is responsible for the production of ribosomes.
- It is composed of proteins and RNA. RNA is used to produce ribosomal RNA (rRNA) which is then combined with proteins to make the ribosomes necessary for protein synthesis.
Outline the structure and function of the nuclear envelope.
- The nuclear envelope contains pores which allow molecules to move in and out of the nucleus.
- protects the nucleus from damage in the cytoplasm
Outline the structure and function of the rough endoplasmic reticulum.
Structure:
- A system of membranes enclosing a flattened sacs called cisternae.
- The surface is covered with ribosomes.
Function:
- Fold and processes proteins that have been made at the ribosomes
Outline the structure and function of the smooth endoplasmic reticulum
Structure:
- Similar to RER (A system of membranes enclosing a flattened sacs called cisternae) but no ribosomes
Function:
- Synthesizes, processes and stores lipids and carbohydrates
Outline the structure and function of the golgi apparatus.
Structure:
- A group of fluid filled membrane-bound flattened sacs. Vesicles are often seen at the edges of the sacs.
Function:
- It processes, modifies and package new lipids and proteins into vesicles. It also makes lysosomes.
Outline the structure and function of the ribosomes
Structure:
- Very small organelle that either floats free in the cytoplasm or is attached to the RER.
- It is made of proteins and RNA. It is not surrounded by a membrane.
Function:
- The site where proteins are made
Outline the structure and function of the mitochondria
Structure:
- Usually oval shaped, has a double membrane to give a large surface area
- the inner membrane is followed to form structure called cristae
- inside is a matrix which contains enzymes involved in respiration
Function:
- the site of aerobic respiration where ATP is produced
- Found in very large numbers in cells that are very active and require a lot of energy
Outline the structure and function of the lysosomes
Structure:
- a round organelle surrounded by a membrane, with no clear internal structure
Function:
- Contains hydrolytic enzymes. These are kept separate from the cytoplasm by the surrounding membrane.
- Can be used to break down invaders in the cells or break down worn out components of the cell.
Outline the structure and function of the chloroplasts.
Structure:
- A small flattened structure found in plant cells.
- It is surrounded by a double membrane and also has membranes inside called thylakoid membranes.
- These membranes are stacked up in some parts of the chloroplast to form grana. Grana are linked together by lamellae - thin, flat pieces of thylakoid.
Function:
- The site where photosynthesis takes place. Some parts of photosynthesis happen in the grana, and other parts happen in the stroma (a thick fluid found in the chloroplasts)
Outline the structure and function of the plasma membrane
Structure:
- The membrane found on the surface of animal cells and just inside the cell wall of plant cells and prokaryotic cells.
- It is mainly made of lipids and proteins
Function:
- Regulates the movement of substances in and out of cell. It also has receptor molecules on it, which allow it to respond to chemicals like hormones.
Outline the structure and function of the centrioles.
Structure:
Small, hollow cylinders made of microtubules (tiny protein cylinders). Found in animal cells, but only some plant cells.
Function:
Involved with the separation of chromosomes during cell division.
Outline the structure and function of the cell wall
Structure:
A rigid structure that surrounds plant cells. It is made mainly of carbohydrate cellulose. Fully permeable.
Function:
Supports plant cells.
Outline the structure and function of the flagella
Structure:
- Flagella are like cilia but longer.
- They stick out from the cell surface and are surrounded by the plasma membrane.
- They are made of two microtubules in centre and nine pairs around the edge.
Function:
- The microtubules contract to make the flagellum move. The flagella are used like overboard motors to propel cells forward (e.g. when a sperm cell swims)
Outline the structure and function of the cilia
Structure:
- small hair-like structures found on the surface membrane of some animal cells. In cross-section, they have an outer membrane and a ring of nine pairs of protein microtubules inside, with a single pair of microtubules in the middle
Function:
- The microtubules allow the cilia to move. This movement is used by the cell to move substances along the cell surface.