2.1 foundations in biology,
the ultrastructure of eukaryotic cells and the functions of the different cellular
components
Plant cell sub cellular structures
Chloroplast
Function
– responsible for producing energy by photosynthesis.
-Uses carbon dioxide, water, and light energy to build sugars.
Structure
- chloroplasts are bounded by a double membrane known as the chloroplast envelope
inside is a colorless matrix — the stroma.
- floating in the stroma are thylakoids which stack together to form a granum.
- The grana can be interconnected by tubular extensions called Intergranal lamellae,
-also present are starch grains which act as temporary stores for the carbohydrates
formed during photosynthesis.
Additional information
Chloroplasts have ribosomes and small circular chromosomes of DNA formally known
as extranuclear DNA for protein synthesis needed for both replication of chloroplast and
photosynthesis.
There are two main different stages of photosynthesis in the chloroplast
- The light dependent stage takes place in the thylakoids
- The light independent stage takes place in the stroma
Vacuoles
Function
- responsible for keeping the cell firm (turgid)
Structure
, - A vacuole consists of a membrane called the tonoplast, filled with cell sap - (a watery
solution of different substances, including sugars, enzymes and pigments.)
Additional information
-Permanent vacuoles only exist in plant cells. Animal cells can contain temporary
vacuoles however they are not very common.
Cell wall
Function
- The cell wall of a plant cell gives it support and structure.
structure
-The cell wall is made of polysaccharide cellulose and can function as a carbohydrate
store by varying the amount of cellulose it holds.
-The cell wall does not seal off a cell completely from its neighbors. There are pores
within the walls called plasmodesmata. These connect two cells together by their
cytoplasm, enabling the exchange and transport of substances.
Additional information
-The cell wall is permeable to most substances such as oxygen and carbon dioxide.
Animal cells sub cellular structures.
Nucleus
Function
-the nucleus controls the cell's activities
Structure
- the nucleus is surrounded by a double membrane called the nuclear envelope’
the ultrastructure of eukaryotic cells and the functions of the different cellular
components
Plant cell sub cellular structures
Chloroplast
Function
– responsible for producing energy by photosynthesis.
-Uses carbon dioxide, water, and light energy to build sugars.
Structure
- chloroplasts are bounded by a double membrane known as the chloroplast envelope
inside is a colorless matrix — the stroma.
- floating in the stroma are thylakoids which stack together to form a granum.
- The grana can be interconnected by tubular extensions called Intergranal lamellae,
-also present are starch grains which act as temporary stores for the carbohydrates
formed during photosynthesis.
Additional information
Chloroplasts have ribosomes and small circular chromosomes of DNA formally known
as extranuclear DNA for protein synthesis needed for both replication of chloroplast and
photosynthesis.
There are two main different stages of photosynthesis in the chloroplast
- The light dependent stage takes place in the thylakoids
- The light independent stage takes place in the stroma
Vacuoles
Function
- responsible for keeping the cell firm (turgid)
Structure
, - A vacuole consists of a membrane called the tonoplast, filled with cell sap - (a watery
solution of different substances, including sugars, enzymes and pigments.)
Additional information
-Permanent vacuoles only exist in plant cells. Animal cells can contain temporary
vacuoles however they are not very common.
Cell wall
Function
- The cell wall of a plant cell gives it support and structure.
structure
-The cell wall is made of polysaccharide cellulose and can function as a carbohydrate
store by varying the amount of cellulose it holds.
-The cell wall does not seal off a cell completely from its neighbors. There are pores
within the walls called plasmodesmata. These connect two cells together by their
cytoplasm, enabling the exchange and transport of substances.
Additional information
-The cell wall is permeable to most substances such as oxygen and carbon dioxide.
Animal cells sub cellular structures.
Nucleus
Function
-the nucleus controls the cell's activities
Structure
- the nucleus is surrounded by a double membrane called the nuclear envelope’
