Cells Flashcards
What 3 main ideas does the Cell Theory include?
- All living organisms are made up of one or more cells
- Cells are the basic functional unit of all living organisms
- New cells are produced from pre-existing cells
What are the features of the nucleus?
Nuclear Envelope: Double membrane surrounding nucleus, controls movement of substances
Nuclear Pores: Allow passage of large molecules
Nucleoplasm: Jelly like material making up most of nucleus
Nucleolus: Manufactures RENAULT and assembles ribosomes
What are the functions of the nucleus?
- Control centre if the cell
- Contain genetic material in form of DNA and chromosomes
- Manufactures rRNA and ribosomes
What are the features of mitochondria?
Cristae: Double membrane with folded inner membrane
Matrix: Formed from cristae, allows mitochondria to control making of its own proteins
What is the function of mitochondria?
- Site of aerobic respiration
- Responsible for production of ATP
What are the features of chloroplasts?
Thylakoid membranes: Where the light dependant reaction takes place, contains chlorophyll
Grana: Stacks of thylakoid membranes, provide a large surface area
Stroma: Fluid where the light independent reaction takes place, possess enzymes
What is the function of chloroplasts?
- Carry out photosynthesis
- Can easily manufacture some proteins needed for photosynthesis
What are the features of smooth and rough endoplasmic reticulum (SER/RER)?
RER:
- Surface covered in ribosomes
- Continuous folds of membrane with nuclear envelopes, large surface area
- Provides transport pathway for proteins
SER:
- Does not have ribosomes on the surface
What is the function of RER/SER?
RER:
1. Large SA for synthesis of (glyco)proteins
2. Processes proteins made by ribosomes
SER:
1. Synthesis, store and transport of lipids and carbohydrates
What is the function of RER/SER?
RER:
1. Large SA for synthesis of (glyco)proteins
2.
What are the features of golgi apparatus?
Similar structure to SER (lacks ribosomes) but more compact
Cisternae: Flattened membranes that make up flattened sacks with small, hollow vesicles
What is the function of golgi apparatus?
- Modifies and transports proteins - adds carbohydrates to form glycoproteins
- Labels and sorts proteins to be sent to correct destinations
- Produce secretory enzymes
- Secrete carbohydrates
- Transport, modify and store lipids
- Form lysosomes
What are the features of ribosomes?
80S found in eukaryotes
70S, smaller, found in prokaryotes
Complex of rRNA and proteins
What is the function of ribosomes?
- Site of protein synthesis
What is the function of lysosomes?
- Special form of vesicles that contain hydrolytic enzymes
- Hydrolyse material ingested by phagocytes
- Release enzymes to outside of cells to destroy material around cell
- Disaster worn out organelles and break down dead cells
What are the features of the cell wall?
Cellulose microfibrils that contribute to strength
Many polysaccharides
Middle lamella: Cements adjacent cells together
What is the function of a cell wall?
- Provides mechanical strength to prevent vell from bursting under pressure
- Mechanical strength to cell overall
- Allows water to pass along, contributes to water movement
What is the function of a vacuole?
- Sac in plant cells with partially permeable membrane
- Sugars and amino acids may act as temporary food source
Support herbaceous plants
What is a specialised cell?
A cell that becomes specialised in structure to suit the rile that it will carry out
What is the organisation of cells?
- Cells
- Tissues: A number of similar cells working together to perform a particular function
- Organs: A group of tissues working together to perform a particular function
- Organ system: Organs that work together to perform particular functions more efficiently
What is the function of a nerve cell and its adaptations?
Function: Conduction of impulses
Adaptations:
- Cell body: Where most cellular structures are located and most protein synthesis occurs
- Dendrites: Allows neurones to communicate with other nerve cells
- Axon: Covered in fatty myelin sheath which speeds up nerve impulses
What is the function of a muscle cell and its adaptations?
Function: Contraction for movement
Adaptations:
- Layers of proteins filaments: Can slide over each other causing muscle contraction
- Lots of mitochondria: Sufficient energy for muscle contraction
What is the function of a sperm cell and its adaptations?
Function: Reproduction - to fuse with egg
Adaptations:
- Head containing nucleus: Containing half number of chromosomes
- Lots of mitochondria: Energy for tail movement
What is the function of a root hair cells and its adaptations?
Function: Absorption of water and mineral ions
Adaptations:
- Root hair: Increase surface area to absorb more water
- Mitochondria: For active transport of mineral ions
- Thin water: Short diffusion pathways
