Cell structure Flashcards
Define the term eukaryotic cell
Cells with a nucleus and other membrane bound organelles
Define the term ultrastructure
They are the features of a cell which can be sen using an electron microscope
Draw diagrams of a typical plant and animal cell, labelling the structures
http://www.sheppardsoftware.com/health/anatomy/cell/plant_cell_game.htm
Find a labelling activity online
Outline the structure and functions of the nucleus
Structure
1. has a double membrane (nuclear envelope)
2. it has pores- nuclear pores
3. the nucleus contains chromatin which is made form DNA and proteins
4. it often contains a nucleolus
Function
1. Controls cell activities
2. contains instructions to make proteins
3. the pores allow substances (RNA) to move between the nucleus and the cytoplasm
Outline the structure and functions of the nucleolus
- It is and area in the nucleus and is responsible for producing ribosomes.
- composed of proteins and RNA
- RNA is used to produce ribosomal RNA (rRNA) which is then combined with proteins to form the ribosomes necessary for protein synthesis
Outline the structure and functions of the nuclear envelope
- the nuclear envelope contains pores which allow molecules to move into and out of the nucleus.
- it also protects the nucleus from damage in the cytoplasm
Outline the structure and functions of the rough endoplasmic reticulum
Structure
1. A system of membranes enclosing flattened sacs called cisternae
2. the surface is covered with ribosomes
Functions
1. Folds and processes proteins that have been made at the ribosomes
Outline the structure and functions of the smooth endoplasmic reticulum
Structure
1. Similar to RER but with no ribosomes
Function
1. Synthesises and processes and stores lipids and carbs
Outline the structure and functions of the golgi apparatus
Structure
1. A group of fluid-filled, membrane bound, flattened sacs
2. Vesicles are often seen at the edges of the sacs
Function
1. It processes and packages new lipids and proteins into vesicles
2. It also makes lysosomes
3. It modifies proteins
Outline the structure and functions of ribosomes
Structure 1. Very small organelle that either floats free in the cytoplasm or is attached to the RER 2. It is made up of proteins and RNA 3. Not surrounded by a membrane Function 1. the site where proteins are made
Outline the structure and functions of mitochondrian
Structure
1. Usually oval shaped
2 has a double membrane - the inner one is folded to form structures called cristae
3. inside is a matrix, which contains enzymes involved in Respiration
Function
1. Site of aerobic Respiration where ATP is produced
2. Found in very large numbers in cells that are v active and require a lot of energy.
Outline the structure and functions of lysosomes
Structure
1. A round organelle surrounded by a membrane with no clear internal structure
Function
1. Contains digestive enzymes which are kept separate from the cytoplasm by the surrounding membranes. they can be used to digest invading cells or to break down worn out components of the cell.
Outline the structure and functions of the chloroplasts
Structure
1. Small, flattened structure found in plant cells.
2. surrounded by a double membrane
3. also has membranes inside called the thylakoid membranes
4. these membranes are stacked up in some parts of
the chloroplast to form grana.
5. Grana are linked together by lamellae- thin, flat pieces of thylakoid membrane
Function
1. Site of Photosynthesis
2. Some parts of photosynthesis happen in the grana
3. Other parts happen in the stoma (a thick fluid found in chloroplasts)
Outline the structure and functions of the plasma membrane
Structure
1. The membrane found on the surface of animal cells and just inside the cell wall of plant cells and prokaryotic cells
2. It’s made mainly of proteins and lipids
Functions
1. Regulates the movement of substances into and out of the cell.
2. it also has receptor molecules on it, which allow it to respond to chemicals like hormones
Outline the structure and functions of the centrioles
Structure
1. Small, hollow cylinders, made of microtubules (tiny proteins cylinders)
2. found in animal cells but only some plant cells
Function
1. involved with the separations of chromosomes during cell division
Outline the structure and functions of the cell wall
Structure
1. A rigid structure that surrounds plant cells
2. It’s made mainly of carbohydrate cellulose
Function
1. Supports plant cells
Outline the structure and functions of the flagella
Structure
1. Flagella are like cilia but longer
2. they stick out from the cell surface and are surrounded by the plasma membrane
3. Inside they have two microtubule in the centre and 9 pairs around the edge
Functions
1. Microtubules contract to make the flagellum move.
2. they are like outboard motors to propel cells forward
Outline the structure and functions of the cilia
Structure
1. small, hair like structures found on the surface membrane of some animal cells
2. in the 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
Functions
1. the microtubules allow the cilia to move. this movement is used by the cell to move substances along the cell surface
State 3 similarities and 3 differences between a typical plant and animal cell.
Similarities 1. both have nucleus 2. both have plasma membrane 3. both have cytoplasm differences 1. plants also have chloroplasts 2. plants have a cell wall 3. Plants have a large permanent vacuole
Draw and label a diagram of a mitochondrion.
look at book and draw it
. Draw and label a diagram of a chloroplast
look at book and draw it
Draw a diagram showing the relative sizes of different cellular components.
Nucleus, mitochondria and chloroplast are big
ribosomes are smallest
vacuole in plant cell is the biggest
Identify organelles from images produced by light microscopy, TEM and SEM.
Practice this
online quizzes
Protein production
- Nucleus- Transcription- DNA is converted to mRNA and is sent out of the nucleus into cytoplasm via the nuclear pores
- Ribosomes on RER- mRNA attaches to the ribosomes and proteins are made (translation)
- RER- proteins are folded and processed in the RER. then they are transported from the RER to the cis face of the Golgi apparatus in vesicles
- Golgi apparatus- proteins may undergo further processing (e.g sugar chains are trimmed or more are added)
- Proteins leave the Golgi apparatus from the transface in the secretory vesicles
- Secretory take the finished proteins to the plasma membrane where they undergo exocytosis and leave the cell
