Science Flashcards
what is cell theory?
- All living things are made up of one or more cells and their products
- The cell is the simplest unit that can carry out all life processes
- All cells come from other cells; they do not come from non-living matter
Prokaryotic cells
No nucleus or membrane bound organelles (e.g. bacteria)
Very simple and small
Organisms are single-celled
Eukaryotic cells
Has a nucleus and other organelles, each surrounded by a thin membrane (e.g. plant & animal cells)
Cells have a more complex organization than prokaryotes
Organelles exist to perform a specific function within a cell
Can be single-celled or multicellular organisms
what are the 2 kingdoms of prokaryotic cells
Archaea
Bacteria
what are the 4 kingdoms of Eukaryotic cells
Protists (unicellular)
Fungi
Plants
Animals
characteristics of living things
Movement
Respiration
Sensitivity
Growth
Reproduction
Excretion
Nutrition
what is an organelle?
An organelle is a cell structure that performs a specific function for the cell
cytoplasm
Jelly-like substance that fills cells
All the organelles in the cell are suspended in the cytoplasm
Allows for cell reactions to occur
cell membrane
Supports the cell
Double layered
Allows some substances to enter while keeping others out of the cell
Referred to as semi-permeable membrane
nucleus
- Control centre of the cell
- Has a semi-permeable membrane known as the nucleus membrane
- Contains genetic information that controls all cell activities
- Contains DNA/Chromatin
nucleolus
Area inside the nucleus where ribosomes are made
mitochondria
- The “powerhouse” of the cell
- Makes energy available to the cells
- Sugars are converted into usable energy (ATP)
- Cite of cellular respiration
endoplasmic reticulum
- Network of tubes that runs through the cytoplasm from the nuclear membrane to the cell membrane
- Used for transporting material and proteins
- In the brain the ER assists with the production of hormones
- In the muscles the ER is involved with muscle contraction
- Involved in protein and lipid synthesis
what is usually attached to the ER
ribosomes
what are the 2 types of ER and what is the difference?
Smooth ER: no ribosomes
Rough ER: has ribosomes
golgi bodies
- Collect and process materials to be removed from the cell
- Makes and secrete mucus
- It modifies proteins and lipids (fats) that have been built in the ER and prepares them for export outside of the cell or for transport to other locations in the cell
vacuoles
- A single layer of membrane enclosing fluid in a sac
- The functions of vacuoles vary greatly
- These include storage of food or wastes of water, removing waste from cell or maintaining cell pressure
what is the difference between plant and animal cell’s vacuoles?
Animal cells: small vacuoles
Plant cells: one large central vacuole
cell wall
Located just outside the cell membrane; provides support and protection for the cell
do both animal and plant cells have a cell wall?
only plant cells
chloroplasts
- Contain chlorophyll and give leaves their green colour
- Absorb light energy
- Site of photosynthesis