Ch 1 Cell Structure and Organisation Flashcards
Cell definition?
A cell is a unit of life. It is made of a mass of living matter called protoplasm.
11 parts of a cell?
- Nucleus
- Cytoplasm
- Chloroplast
- Vacuole
- Cell membrane
- Cell wall
- Rough Endoplasmic Reticulum
- Smooth Endoplasmic Reticulum
- Ribosomes
- Golgi Apparatus
- Mitochondria
Protoplasm is made up of 3 parts:
- Cell membrane
- Cytoplasm
- Nucleus
Features of cell membrane?
- Made of lipids and proteins
- Partially permeable
- Allows small and soluble substances to pass through
- Contains carrier proteins to help in active transport of substances
Features of cell wall?
- Made of cellulose
- Fully permeable
- Protects cell from injury
- Gives cell a fixed shape
- Only present in plant cells
Features of cytoplasm?
- Found between cell membrane and nucleus
- Cellular activities take place here
- Contains organelles
Features of nucleus?
- Controls cell activities
- Essential for cell division
- Cells w/o a nucleus e.g. red blood cells are unable to divide
- Contains chromosomes that contain DNA which carry genetic information
Features of Rough Endoplasmic Reticulum?
- Surface appears studded as ribosomes are attached to it
- Transport proteins made by the ribosomes to the Golgi Apparatus
Features of ribosomes?
- Small round structures
- Either attached to RER or lie freely in cytoplasm
- Responsible for synthesis of polypeptides from amino acids (amino acids -> polypeptides)
Features of Smooth Endoplasmic Reticulum?
- SER is more tubular than RER
- Does not have ribosomes attached to its surface
- Synthesises substances such as
fats and steroids - Involved in detoxification
Features of Golgi Apparatus?
- Golgi apparatus consists of
flattened spaces surrounded by
membranes - Chemically modifies substances made
by the RER and SER - Stores and packages the
substances in vesicles for
secretion out of the cell
Process of proteins made by the RER and SER leaving the cell?
- Vesicles containing proteins made by the RER and SER pinch off from the ER
- Vesicles fuse with the Golgi Appparatus and the proteins are released into the Golgi Apparatus to be chemically modified
- Vesicles containing chemically modified proteins pinch off from the Golgi Apparatus and move towards the cell membrane
- The vesicles fuse with the cell membrane and the proteins within exit the cell
Features of mitochondria?
- Oval/sausage-shaped organelles
- Aerobic respiration occurs here
- Oxidises glucose to release energy for cellular activities
Similarities between generalised animal and plant cell?
Both contain:
- SER
- RER
- Nucleus
- Mitochondria
- Ribosomes
- Golgi Apparatus
- Vacuole
- Cell membrane
- Cytoplasm
Differences between generalised animal and plant cell?
Plant cell:
1. Chloroplasts
2. Cell wall
3. Large central vacuole
Animal cell:
1. No chloroplasts
2. No cell wall
4. Numerous small temporary vacuoles
Red blood cell adaptations and functions?
A1: Contains haemoglobin
F1: Binds reversibly to oxygen
and transports it from
lungs to rest of body
A2: Circular biconcave shape
F2: Increase SA:V ratio for increased rate of diffusion of oxygen in and out of the cell
A3: Absence of nucleus
F3: Allows more space packing of more haemoglobin for
transport of more oxygen
A4: Flexible
F4: Easily squeeze through capillaries
Muscle cell adaptations and functions?
A1: Contain many mitochondria
F1: Provide energy for contraction of muscle cell
A2: Has contractile protein fibres
F2: Contract and relax to bring about movement
A3: Has many nuclei
F4: Allow for cell division
Root hair cell adaptations and functions?
A1: Long and narrow extension / protrusion
F1: Increase surface area-to-
volume ratio for increased rate of absorption of water and mineral salts
A2: Large number of mitochondria
F2: Provide energy for active transport of mineral salts
A3: Maintains a lower water potential in vacuole
F3: Allow water to enter the
root hair cell via osmosis
