2. Cells Flashcards
What are the requirements for living things?
Movement, respiration, sensitivity, growth, reproduction, excretion, equilibrium, nutrition
What are cells?
cells are the basic units of all life, most cannot be seen with the naked eye, use microscopes to look in more detail
Cell theory (3 points)
the smallest living organisational unit
all organisms are composed of cells
all cells come from pre-existing cells
Plant cells
cell wall, chloroplasts, large vacuole
some plants use chloroplasts for photosynthesis
Animals cells
don’t have cell wall
just a membrane
Prokaryotic cells
3.8 billion years ago
bacteria= main type
unicellular/cell wall/ X nucleus
eukaryotic cells
2.7 billion years ago developed
single or multicellular
membrane bound organelles
organelles
cells have different organelles
every cell surrounded by plasma membrane
substance fluid called cytosol contains dissolved salts, nutrients and molecules for cell function
Biomolecules
all living things are built of 4 organic bio-molecules based on carbon atom
1. COH- simple sugars
2. lipids-fatty acids and glycerol
3. proteins- amino acids
4. nucleic acids
units of biology
cells –> tissues —> organs —> body system —> organisms
Prokaryotic cells def and example
developed over 3.8 billion years ago
bacteria is the main type of prokaryotic cells
unicellular organisms with a cell wall but no nucleus
eg. cyanobacteria
Eukaryotic cells def and example
developed over 2.7 billion years ago
can be single or multi-cellular
membrane bound organelles
eg. plants or animals
key difference between the plant cells
plant cells have a cell wall as well as a membrane where animals only have a membrane/ plants have larger vacuoles to hold nutrients, water and waste. Some plant cells contain chloroplasts which enable the organisms to create energy through photosynthesis
