Cells Flashcards
Which organelles are specific to plant cells?
Chloroplasts, large central vacuole , tonoplast, cell wall
What are chloroplasts?
Oval structures containing chlorophyll which absorbs light energy to carry out photosynthesis
What’s a cell wall and its function?
A fully permeable cellulose structure that encloses the entire plant cell, surrounding the cell surface membrane.
It protects the cell from injury and
Gives the plant cell a fixed shape
What can be identified under a electron microscope?
Smaller structures like ribosome, endoplasmic reticulum, centrioles and Golgi bodies
What can be identified under a light microscope?1
Main structures like cell walls, vacuoles cytoplasm, chloroplasts,nucleus and cell membrane
What is the cell surface membrane and its function ?
A partially permeable membrane made up of lipids and proteins that surrounds the cytoplasm and forms the boundary of the cell, holding the contents of the cell in its place.
It regulates the movement of substances entering and leaving the cell
What is the function of the nucleus?
Controls cell activities like cell growth and the repair of worn out parts, protein synthesis
Essential for cell division
What are chromatin?
A network of threadlike structures that controls cell activities like cell growth, cell division and protein production
It is made up of deoxyribonucleic acid / DNA which carries hereditary information
Chromatin threads coils and condense into chromosomes when the cell divides
What is the function of the RER?
It transports proteins to the Golgi apparatus for secretion out of the cell
What are ribosomes and its function?
Small round structures either attached to the membrane of the endoplasmic reticulum or free-lying in the cytoplasm
They synthesise proteins in the cell
Those attached to the ER makes proteins that are usually transported out of the cell and
Those lying freely in the cytoplasm makes proteins that are used within the cell
What is are the functions of the smooth endoplasmic reticulum?
Synthesises substances such as fats and steroids
Converts harmful substances into harmless materials (detoxification)
What is the function of the Golgi apparatus/golgi body?
Chemically modifies substances made by the ER,
Stores and packages substances in vesicles for secretion out of the cell
How does substances made in the endoplasmic reticulum secreted out of the cell?
Vesicles transport substances within the cell. Small vesicles containing substances made by the ER are pinched off from the ER
These vesicles then fuse with the Golgi apparatus and release their contents into the Golgi apparatus.
The substances made by the ER may be modified inside the Golgi apparatus
Secretory vesicles containing these modified substances are pinched off from the Golgi apparatus. They then move to the cell surface membrane
The secretory vesicles fuse with the cell surface membrane and their contents are released outside the cell
What is the function of the mitochondria?
Site of aerobic respiration where glucose is oxidised to release energy
What is the function of vacuoles?
Stores substances within the cell like water,food, waste substances and mineral salts
