Summary of descriptions and functions of cellular structures
Cellular Component | Descriptions & Functions |
Plasma Membrane | - made of protein and phospholipids - semi permeable = selective barrier Function: regulate movement of substance in and out of cytoplasm |
Cell Wall | - permeable to all fluids ( has tiny pores) Function: 1. gives shape 2. provide mechanical support 3. protect the plant cell from rupturing due to excessive intake of water |
Cytoplasm | - contain organic and inorganic substances Function: 1. Acts as medium for biochemical reactions in the cell 2. Provide substances obtained from the external environment to the organelles. |
Nucleus | Function of Nucleus: Controls all the activities which take place in the cell Consists of 1. Nuclear membrane 2. Nucleolus 3. Chromatin (the form that chromosomes take when the cell is not dividing, is contain within nucleoplasm 4. Chromosomes Function of Chromosomes: a. Carry genetic information which determines the characteristics and functions of a cell. b. contain coded information which regulate synthesis of protein |
Vacuole |
Types of vacuole 1. Contractile vacuole : a. help to regulate water balance in these organisms. b. acts as a storage place in a cell 2. Food vacuole : storage pocket for food |
Mitochondria | Function: release energy by going through process of cellular respiration (when food substances such as glucose are broken down with the help of enzymes present in mitochondria) - energy released stored in the form of ATP (adenosine triophosphates) that can be readily used by cells. |
Ribosomes |
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Endoplasmic Reticulum | Two types of endoplasmic reticulum: 1. Rough Endoplasmic Reticulum ( rough ER)
2. Smooth Endoplasmic Reticulum ( smooth ER)
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Golgi Apparatus | Function:
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Lysosomes | Function:
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Centrioles | - composed of a complex arrangement of microtublules - does not present in plant cell. Function:
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Chloroplasts | - contain green pigment chlorophyll Function of chlorophyll in chloroplasts:
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Comparison of animal and plant cells
Similarities | ||
have plasma membrane, cytoplasm, nuclues, endoplasmic reticulum, Golgi apparatus, ribosomes and mitochondria.
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Differences | ||
Animal cells | Aspect | Plant cell |
Flexible | Shape | Fixed |
Absent | Cell wall | Present |
Absent | Chloroplast | Present |
If present, are scattered throughhout the cell | Vacuole | Has one or few large vacuole(s) |
Present | Lysosome | normally absent |
Present | Centriole | absent |
Relation between number of certain organelles with the functions of specific cells
Types of cells | Function | Organelles found abudantly in the specific cells |
Sperm cells | Require large amounts of energy to propel towards the uterus and Fallopian tube during fertilisation | Mitochondria |
Flight muscle cells in insects and birds | Contract and relax to enable movements and flight | Mitochondria |
Cells in the meristems | Divides actively | Mitochondria |
Mesophyll palisade cells | Catch the energy from the sunlight for photosynthesis | Chloroplasts |