Topic 2- Eukaryotic cells and organelles+ specialised cells Flashcards
Are Eukaryotic or prokaryotic cells more complex?
Eukaryotic
Give some examples of Eukaryotic cells
-Animal cells
-Plant cells
-Algal cells
-Fungal cells
-Epithelial cells
What are the extra organelles in plant cells?
-A cellulose cell wall with plasmodesmata (channels for exchanging substances between adjacent cells)
-A vacuole (fluid-filled compartment)
-Chloroplasts
What is the function of an algal cell?
Carry out photosynthesis but can be multicellular or unicellular
What is the main difference between plant cells and algal cells?
The chloroplasts are of different shapes and sizes
Are fungi cells multicellular or unicellular?
Both
What are the differences between plant cells and fungal cells?
-cell walls are made of chitin, not cellulose
-they don’t have chloroplasts as they don’t photosynthesise
What is the structure of a cell surface membrane?
-(also called the plasma membrane)
-The membrane found on the surface of animal cells and just inside the cell wall of other cells
-Phospholipid bilayer
What is the main function of the cell surface membrane?
-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 such as hormones
What is the structure of the nucleus?
-A large organelle surrounded by a nuclear envelope (double membrane), which contains many pores
-The nucleus contains chromosomes which are made up of protein-bound linear DNA and one or more structures called a nucleolus
What is the function of the nucleus?
-Controls the cell’s activities by controlling the transcription of DNA
-DNA contains the instructions to make proteins
-The pores allow substances (eg. RNA) to move between the nucleus and the cytoplasm
-The nucleus makes ribosomes
What is the structure of the mitochondrion?
-Usually oval-shaped
-Usually have a double membrane, the inner one is folded to form structures called cristae
-Inside is the matrix which contains enzymes involved in respiration
What is the function of the mitochondrion?
-The site of aerobic respiration
-Aerobic respiration produces ATP- a common energy source in the cell mitochondria are found in large numbers in cells that are very active and require a lot of energy
What is the structure of the chloroplast?
-A small, flattened structure found in plant cells and algal cells
-Surrounded by a double membrane and also has membranes called thylakoid membranes
-These membranes are stacked up in some parts of the chloroplast to form grana
-Grana are linked together by lamella which are thin, flat peices of thylakoid membranes
What is the function of the chloroplast?
-The site of photosynthesis
-Some parts of photosynthesis happen in the Grana and other parts happen in the stroma( a thick fluid found in the chloroplast)
What is the structure of the Golgi apparatus?
-A group of fluid-filled membrane-bound flattened sacs
-Vesicles are often seen at the edge of the sacs
What is the function of the Golgi apparatus?
-It processes and packages new lipids and proteins
-It also makes lysosomes
What is the structure of a Golgi vesicle?
A small fluid-filled sac in the cytoplasm surrounded by a membrane and produced by the Golgi apparatus
What is the function of a Golgi vesicle?
-Stores lipids and proteins made by the Golgi apparatus and transports them out of the cell (via the cell surface membrane)
What is the structure of a lysosome?
`A round organelle surrounded by a membrane with no clear internal structure
What is the function of a lysosome?
-Contains hydrolytic enzymes
-These are kept separate from the cytoplasm by the surrounding membrane and can be used to digest invading cells or to break down worn-out components of the cell
What is the structure of a ribosome?
-A very small organelle that floats free in the cytoplasm or is attached to the rough endoplasmic reticulum
-It is made up of proteins and RNA
-It is not surrounded by a membrane
What is the function of a ribosome?
-Were proteins made/protein synthesis
What is the structure of the rough endoplasmic reticulum (RER)?
-A system of membranes enclosing a fluid-filled space
-The surface is covered with ribosomes
What is the function of the RER?
-Folds and processes proteins that have been made at the ribosomes
What is the structure of the Smooth endoplasmic reticulum (SER)?
-Same as RER but does not have ribosomes on the surface
What is the function of the SER?
-Synthesises and processes lipids
What is the structure of the cell wall?
-A rigid structure that surrounds cells in plants, algae and fungi
-In plants and algae made mainly of the carbohydrate cellulose
-In fungi, it is made of chitin
What is the function of the cell wall?
-Supports cells and prevents them from changing shape
What is the structure of a cell vacuole?(plants)
-A membrane-bound organelle found in the cytoplasm
-Contains cell sap, a weak solution of sugar and salts
-The surrounding membrane is called the tonoplast
What is the function of the cell vacuole?
-Helps to maintain pressure inside the cell and keep the cell rigid, this stops the plant from wilting
-It is also involved in the isolation of unwanted chemicals inside the cell
What types of cells can become specialised to carry out specific functions?
Multicellular eukaryotic organisms
Where are epithelial cells located and what are they specialised for?
-in the small intestine and are adapted to absorb food efficiently
What are the adaptions of an epithelial cell?
-The walls of the small intestine have lots of villi which increase surface area for absorption
-The epithelial cells on the surface of the villi have folds in their cell surface membrane called microvilli which increase the surface area even further
-They also have lots of mitochondria to provide energy for the transport of digested food molecules in the cell
What are the adaptions of red blood cells?
-Adapted to carry oxygen around the body
-They have no nucleus to make more room for the oxygen-carrying compound haemoglobin
What are the adaptions of sperm cells?
-Contain lots of mitochondria to provide the large amounts of energy (ATP) they need to propel themselves towards the egg
What is the chain of cell organisation?
specialised cells, tissues, organs, and organ system
What is a tissue?
a group of cells working together to perform a particular function
