PASS Objectives Content Standard 1.1 Cells are composed of a variety of structures such as the nucleus, cell membrane, cell wall, cytoplasm, ribosomes, mitochondria, and chloroplasts.
1 All living things are made of cells
2 Cells are the basic units of life
3 Cells come only from other cells
All bacteria cells are about the same size
All animal cells are about the same size
All plant cells are about the same size
Larger animals must have MORE cells. 50 Trillion Cells
Summary of Cell Organelles cell wall cell membrane cytoplasm nucleus ribosome mitochondria vacuole lysosome plastid support & protect cell surround the cell fluid inside cell controls the cell (DNA) protein synthesis produce energy storage recycle contain pigment
Cell Wall Surrounds bacteria and plant cells, functions for support and protection.
Cell Wall There are large pores in the cell wall that allow substances to come in contact with the cell membrane.
Cell Membrane A complex barrier of lipid (fat) molecules separating the inside of the cell from its external environment.
Cell Membrane There are two layers of lipid molecules - one forming the inside surface and one forming the outside surface.
Cell Membrane Carbohydrate and protein molecules are part of the membrane and extend through it.
Cell Membrane The membrane is selectively permeable, allowing substances like water and oxygen to move freely through it, while keeping other substances from doing so.
Cell Membrane Water moves through the membrane by the process of osmosis.
Cell Membrane During osmosis, particles move easily from an area of HIGH concentration to an area of LOW concentration by molecular motion only.
Cell Membrane A cell CAN push molecules against this "concentration gradient", but it requires the cell to use energy to do so.
Cytoplasm A thick, aqueous solution of salts surrounding the organelles inside the cell membrane.
Cytoplasm Nutrients and minerals spread through the cytoplasm to all parts of the cell by cytoplasmic streaming...
Cytoplasm meaning the cytoplasm is constantly slowly moving inside the cell.
Nucleus The nucleus directs cell activities.
Nucleus The nucleus contains the DNA of a cell in the form of chromatin, long threads of DNA.
Nucleus Chromosomes form ONLY during cell division.
Ribosome Sites of protein synthesis in almost all cells.
Ribosome These small, spherical structures are the most numerous organelles in most cells.
Endoplasmic Reticulum A system of folded membrane sacs and tunnels in the cytoplasm.
Endoplasmic Reticulum Rough "ER" is covered with ribosomes. Smooth "ER" has few or no ribosomes.
Mitochondria Respiration centers of a cell.
Mitochondria Large organelles scattered through the cell, they are most numerous in cells that use a LOT of energy like liver and muscle cells.
Golgi Apparatus A stack of membranes that act to "package" substances for export from the cell.
Golgi Apparatus Once enclosed in a vesicle, the product is sent through the cell membrane.
Lysosome Lysosomes are the cell's recycling centers.
Lysosome Enzymes inside lysosomes break down molecules into smaller materials that are then used to build new complex molecules.