2.1.1 EK Cells Flashcards
What is a cell that contains a nucleus called?
Eukaryotic Cell
What is a chloroplast?
An oval shaped flattened organelle with a double membrane
Inside it has stacks of membrane (grana) called thylakoid membrane
This is where chlorophyll is found
The stroma is a fluid filled matrix
Function of Chloroplast?
The site of photosynthesis
Chlorophyll absorbs light energy and uses this energy to synthesise glucose
In the stroma the second stage of photosynthesis takes place
What is a mitochondrion?
An oval shaped structure organelle with a double membrane
The inner membrane is folded to form structures called cristae
The inner fluid compartment is called the matrix
Function of Mitochondrion?
The site of aerobic respiration which produces ATP
The matrix contains the enzymes involved in respiration
What is the Golgi apparatus?
A stack of fluid filled membrane bound sacks - cisternae
Vesicles are often seen at the edges of the sacs
Function of Golgi apparatus?
Processes and packages polypeptides and polysaccharides for exocytosis (movement of proteins and carbohydrates)
Also processes lipids and forms lysosomes
The vesicles transport the processed proteins and lipids to the cell surface membrane
What is the vacuole?
A membrane bound organelle found in the cytoplasm
It contains cell sap (sugar and salt solution)
Function of permanent vacuole?
Helps maintain pressure to keep the plant cell turgid
Contains a large volume within a plant cell and is flexible
The site of isolation of unwanted chemicals inside the cell
Function of nucleolus?
Small spherical region in the nucleoplasm
The site of production of rRNA and ribosomes
What is a cell wall?
Surrounds cells in plants, algae and fungi
In plants and algae it is made from cellulose with a thin layer called the middle lamella (boundary between adjacent cell walls)
In fungi it is made from chitin
Has microfibril making it strong
Function of the cell wall?
Supports the cells and prevents them from losing shape giving the plant strength
Allows the cell to become turgid without bursting and with stand pressure
Allows water to pass along
What is a nucleus?
A large organelle surrounded by a double membrane called the nuclear envelope, which contains many pores
It contains genetic material of the cell and one or more nucleoli
Function of the Nucleus?
Controls the cells activities through the production of RNA and ribosomes
Retains the genetic material of the cell as DNA and chromosomes
What is a lysosome?
A type of Golgi vesicle with a membrane made of phospholipids
Inside the vesicle there are enzymes such as lysozymes (hydrolytic enzymes), proteases and lipases
Function of Lysosome?
Hydrolyse material ingested by phagocytic cells
Digest invading cells or worn out organelles
Break down cells after they die
What is a cell-surface membrane?
A bilayer of lipids with proteins embedded in it
Some of these lipids and proteins have carbohydrates attached to them
Function of cell membrane?
Regulates the movement of substances into and out of the cell
It has receptor molecules on the surface to allow it to respond to chemicals like hormones and cell regognition
Function of cytoplasm?
Gel like fluid where cell organelles are found
Function of nuclear pore?
Around 3000 small gaps in the nuclear membrane that allow ribosomes, mRNA and nucleotides to pass in and out of the nucleus
Function of chromatin?
A complex of macromolecules found in the nucleus consisting of DNA, protein and RNA
What is a ribosome?
They are very small organelles floating freely within the cytoplasm or attached to rough endoplasmic reticulum
They are made up of a small and larger subunit
Made up of proteins and RNA
They are not membrane bound
Function of ribosomes?
Where amino acids are synthesised to form proteins
What is the size of the ribosome in an eukaryotic cell?
80S
What is the rough endoplasmic reticulum?
A system of membranes enclosing a fluid filled space creating passageways called cisternae
The surface is covered in ribosomes
Function of rough endoplasmic reticulum?
Provides a network of membranes for transport of polypeptides (long chain amino acids)
Main site of protein synthesis due to the presence of ribosomes
What is the smooth endoplasmic reticulum?
A system of membranes enclosing a fluid filled space
Function of smooth endoplasmic reticulum?
It is the site of synthesising, storing and transporting lipids and carbohydrates
Function of centrioles?
Help in the formation of spindle fibres that separate the chromosomes during cell division - mitosis
Function of nuclear membrane/envelop?
Encloses the nucleus encasing the genetic material
Controls entry and exit of substances in and out of the nucleus
Made of lipids
Function of vacuole membrane?
Encloses the vacuole
Can expanded rapidly to allow the vacuole more volume to hold fluids and nutrients
The surrounding vacuole membrane is called tonoplast
Function of plasmodesmata?
A channel through the cell wall that allows molecules and substances to move back and forth as needed
Allows tissues and organ cells to work together to achieve a common goal
What is a cell?
The smallest structural functional unit of an organism
What is a tissue?
A group/aggregation of similar cells, which carry out a particular function
What are some tissues?
Epithelial
Muscular
Glandular
Connective
What is an organ?
An aggregation of different tissues/cells; carrying out a specific physiological function
What is an organ system?
An aggregation of organs carrying out a specific physiological function more efficiently
What is an organism?
Made up of different organ systems working together
