Cells Flashcards
What is the structure of the cell membrane?
It is built out of protein and phospholipid molecules. It protects the cell.
What is the function of the cell membrane?
It controls the movement of substances (water, food and mineral salt molecules) into and out of the cell. Molecules move across the cell membrane by the process of osmosis.
What is the structure of the cell wall?
In plant cells, the cell membrane is surrounded by a cell wall. The cell wall is non-living. The cell wall is rigid. The cell wall is made up of a carbohydrate called cellulose. Small openings called pits occur in the cell wall.
What is the function of the cell wall?
The cell wall gives support to the cell and makes the cell rigid. It also protects the cell membrane. Pits facilitate the movement of molecules across the cell wall.
What is the protoplasm?
The protoplasm is all the liquid inside the cell. This includes the cytoplasm and nucleoplasm.
What is the cytoplasm?
The cytoplasm is all the liquid inside a cell excluding the liquid inside the nucleus (nucleoplasm). Membrane-covered cell organelles are found floating in the cell cytoplasm.
What is the nucleoplasm?
The nucleoplasm includes all the liquid inside the nucleus.
What are the different plastids?
The different plastids are chloroplasts, leucoplasts and chromoplasts.
What is a chloroplast?
Chloroplasts contain green-coloured molecules called chlorophyll (this is the reason plants are green in colour). Chlorophyll absorbs the sun’s radiant energy which gets converted into chemical potential energy during photosynthesis when glucose sugar is formed.
What is a leucoplast?
Leucoplasts store food for plants in the form of starch.
What is a chromoplast?
Chromoplasts produce colour in plants e.g. the bright colours of flower petals, red tomatoes etc.
What is the structure of vacuoles?
Vacuoles are large fluid-filled cell organelles in plant cells. The fluid inside the vacuole is called cell sap. Cell sap contains water and dissolved nutrient molecules. Vacuole membranes are called tonoplasts. In animal cells vacuoles are much smaller and are called vesicles.
What is the function of a vacuole?
Vacuoles provide water and nutrient storage to the cell. They also give the cell shape due to the outward pressure of the cell sap inside the vacuole.
What is the structure of the nucleus?
The nucleus is surrounded by a double nuclear membrane. It contains a fluid called the nucleoplasm. It contains a nucleolus. It also contains the chromatin network or chromosomes.
What is the function of the nucleus?
The chromatin network or chromosomes are the control centre of each cell. The chromatin network or chromosomes control how each cell functions (in other words control all cell chemical reactions). The chromatin network or chromosomes control the structure of each cell. The chromatin network or chromosomes contain inherited characteristics such as eye colour and hair colour. These characteristics are inherited from the organism’s parents.
