HB PowerPoint 2 Flashcards
What are the 4 Distinct levels of the body?
- Cells: Lowest structural level, specialised 4 functions.
- Tissues: Made of cells with similar specialisation.
- Organs: Made up of 2+ tissues, group together carry out common function.
- Systems: Highest level of organisation, made of group of organs working together.
What does the cell theory state?
The cell theory states that all living things are made up of cells, the basic unit of life, and arise from pre-existing cells.
What is the structure of a cell?
- Cell membrane.
- Cytoplasm
- Cytosol
- Cytoskeleton
- Organelles (vesicles, centrioles, golgi body, mitochondria, ribosomes, etc.)
What is the cell membrane?
Structure: Double layered membrane (bilayer) made up of phospholipids and proteins.
Function: Controls mvmnt of substances in/out of cell, physical barrier between inside and outside.
What is the cytoplasm?
Structure: Thick fluid consisting of cytosol and organelles suspended in it.
Function: Allow chemical reactions to occur, provide shape to cell.
What is Cytosol?
Structure: Consists of 75-95% water with some dissolved substances (e.g. salts).
Function: Metabolic reactions occur here, and controls the osmotic pressure of the cell.
What is nucleus?
Structure: Spherical structure.
Function: Stores genetic material, mostly in the form of DNA.
What is the Nucleolus?
Structure: Small structure in the nucleus.
Function: Contains genetic material, mostly RNA.
What are lysosomes?
Structure: Spherical structures suspended in the cytoplasm.
Function: Contain enzymes that break down materials or worn out organelles.
What is the Endoplasmic reticulum?
Structure: Parallel membranes connecting the cell membrane and nuclear membrane.
Function: Provide a surface for chemical reactions, stores and transports materials.
What are ribosomes?
Structure: Small spheres, free in the cytoplasm or attached to Endoplasmic Reticulum.
Function: Join amino acids together to form proteins.
What are vesicles?
Structure: Small membrane bound sacs.
Function: Transport materials in/out and within the cell.
What is the Golgi Body?
Structure: Stacked, flattened membranes.
Function: Modify and package proteins for secretion.
What are centrioles?
Structure: Pairs of cylinders located near the nucleus.
Function: Involved in cell reproduction.
What is mitochondria?
Structure: Double membraned elongated structures (look like nutri-grain).
Function: Release energy for the cell through cellular respiration.
