CELLS UNICELLULAR A single cell that carries out

CELLS

UNICELLULAR • A single cell that carries out all life processes. – Ex. Amoeba, Paramecium, Euglena

MULTICELLULAR • Made of many cells that work together to carry out all life processes – Ex. Animals, Plants, most Fungi

CELL THEORY • • All living things are made of cells Cells are the basic unit of structure Cells are the basic unit of function Cells come from pre-existing cells

EXCEPTIONS TO THE CELL THEORY • Where did the first cell come from? ? ? • Viruses – Not made of cells – Contain genetic material – Can’t survive on their own (need a host) • Mitochondria & Chloroplasts – Contain some genetic material – Can “reproduce” inside a cell without the whole cell reproducing

TWO KINDS OF CELLS Prokaryotic Eukaryotic No nucleus Smaller Less complex No membrane-bound organelles DNA floats freely in cytoplasm Has nucleus which contains DNA Larger More complex Many different organelles Ex. Bacteria Ex. Amoeba, Plants, Animals

CELL MEMBRANE • Regulates what comes into and goes out of cell • It is SELECTIVELY-PERMEABLE – “Chooses” what it lets in and out • Some molecules are too large to fit • Some molecules are toxic to the cell • Made of lipids and proteins – Officially a “lipid bi-layer” (ooo, fancy…)

CYTOPLASM – Liquid part of cell – Involved in transport • Moving materials around inside a cell is cyclosis – Site of chemical reactions

NUCLEUS • Directs cell activities • Contains the DNA – Nucleolus is found within the nucleus • it makes RNA

RIBOSOMES • Where protein is made • Can be free floating in cell or attached to the E. R.

ENDOPLASMIC RETICULUM • Transports materials throughout the cell – Rough ER • Has ribosomes – Smooth ER • No ribosomes

CHLOROPLASTS • In PLANTS • Site of photosynthesis – Chloroplasts absorb energy from the sun in order to combine CO 2 and H 2 O to make food for the cell

MITOCHONDRIA • Makes ENERGY for the cell – Aerobic respiration takes place here – Remember: ENERGY = ATP

GOLGI BODIES/APPARATUS/COMPLEX • Packages and ships materials for the cell – Think of it as UPS or Fed. Ex. for the cell

VACUOLE • Storage – Stores water, food and waste • Contractile Vacuole – Found in unicellular organisms – Pumps out excess water

LYSOSOME • Breaks down materials • Contains digestive enzymes

CENTRIOLES • Only in ANIMAL cells • Help chromosomes split during cell division

CELL WALL • Support and protection for PLANT cells • Made of cellulose

CYTOSKELETON • Made of protein • Provide support to cell

CILIA • Hair-like microtubules that provide locomotion. • Ex. Paramecium have cilia.

FLAGELLA • Whip-like tail that provides locomotion – Ex. Sperm have a flagella

TRANSPORT IN CELLS • Diffusion = PASSIVE TRANSPORT – Movement of materials from HIGH concentration to LOW concentration. – Little/No energy required

• Osmosis – Diffusion of water

• Active Transport – Requires energy – Phagocytosis • Cells “eating” – Pinocytosis • Cells “drinking”