OPEN SYSTEM
Cells are open systems (can exchange matter and energy with their surroundings)
Cells perform the following life processes… Intake of nutrients Movement Growth Response to stimuli Exchange of gases Waste removal Reproduction
CELL MEMBRANE
Protective barrier for the cell
Allows transport of materials (needed/waste
Cell communication
CYTOPLASM
Gel-like substance inside the cell membrane
Contains nutrients
Holds organelles
Cytoplasmic streaming (movement of molecules)
CHLOROPLAST
Found only in plants and protists
Contain chlorophyll (green pigment)
Site of photosynthesis
VACUOLES AND VESICLES
Store nutrients, fats
Central vacuole in plants stores water
Turgor pressure increases as it takes in water, making the cell turgid
ENDOPLASMIC RETICULUM
Small tubes branching from the nucleus
Materials are transported through it
Rough ER has ribosomes for protein synthesis
Smooth ER – fat and oil production
SEE PAGE 270 – COMPARE PLANT AND ANIMALSimilarities
cell membrane
cytoskeleton made up of proteins and lipids
DNA
Differences
Animals – centrioles
-specialized molecules (hemoglobin/cholesterol)
-glycogen – energy
Plants – cell wall (cellulose)
-starch/oils for energy
-central vacuole
-chloroplasts (chlorophyll)
CHEMICAL COMPOSITION OF CELL STRUCTURES4 major organic compounds…
-lipids (fats/oils)
-carbohydrates (sugars)
-proteins (muscle fibre)
-nucleic acids (DNA)
Water is the other major compound (solvent)
Trace elements
Mg
Zn
Mn
Fe