What is a cell?

Pyramids The Great Pyramids of Egypt are made of stone blocks

Buildings Buildings are put together with bricks....

Nests Birds build their nests with grass, twigs and twine

YOU! Everything is made up of smaller parts.... Even You!

C is for cells.... All living things are made up of cells The cell is the basic unit of structure in all living things All living things are made of cells, so sometimes cells are called the “building blocks” of life The cell is the basic unit of function in all living things All life processes (STRANGER-C) in a living organism are carried out by cells... and cells perform all of life processes on their own as well! Cells come from pre-existing cells

Unicellular Some organisms are made up of only one cell Bacteria Protists

Multicellular Many organisms are made of many different cells which work together

Cell Structure and Function Organelles

Eukaryotes have Organelles YOU are a EUKARYOTE! Eukaryotes have many small, membrane bound structures located inside the cell The structures are called ORGANELLES (which means “little organs”) Organelles perform specific functions which keep the cell (and the organism) alive EU=YOU/NU & PRO=NO

Prokaryotes Have NO organelles Bacteria NO nucleus

(Cytoplasm & Membrane are found in Plant Vs. Animal Some organelles are found only in animal cells Centrioles Lysosomes Others are found only in plant cells Chloroplasts Cell Walls Most organelles, however, are found in both plant AND animal cells (Cytoplasm & Membrane are found in EVERY CELL!)

Cell Membrane (AKA Plasma Membrane) SUPER important! A double-layered structure that surrounds the cell Provides a boundary between the cell and its environment MAIN JOB: To control what goes into and what comes out of the cell!

Tell me more! The cell membrane is SEMI-PERMEABLE which means some substances can pass through it and others cannot It is “selective” about what it allows to get through So it is sometimes said to be “selectively permeable” Small substances pass through easily without using energy... Water Glucose Oxygen Carbon Dioxide

And what's it made of (mostly)? So? What's it look like? And what's it made of (mostly)? Carbohydrates Proteins (make up a channel) Protein Lipid Bilayer

Fluid Mosaic Model Made of a double layer of lipids (fats) which contain large floating protein molecules Because everything is “floating” and can move around, small molecules (water, oxygen, carbon dioxide, glucose) can squeeze through.... Larger molecules (starch, protein) must be digested first!

Life Process: Transport Because the membrane controls the passage of materials into and out of the cell it is part of the “transport system” The membrane is involved in two kinds of transport: Active (which requires energy) Passive (which doesn't!)

Cytoplasm Streaming jelly-like fluid that contains the cell organelles Acts like a “cushion” for the organelles Contains salts and nutrients “Streaming” means it is moving This allows for materials to move around inside the cell Cytoplasm is located between the cell membrane and the nucleus Many life processes (and chemical reactions) take place in the cytoplasm

Nucleus Controls ALL of the cell activities Nicknamed the “Brain” of the cell It is surrounded by its own membrane (nuclear membrane) Acts like a “vault” to store hereditary information (DNA) It contains other organelles (chromosomes and nucleolus) Nucleolus makes Ribosomes

Chromosomes Long threadlike structures located in the nucleus of the cell Contains heredity information organized as genes Genes are hereditary units made of DNA Genes are passed on to the next generation

Mitochondria “Powerhouse” of the cell (the “mighty” mitochondria!) Produces ENERGY (ATP) from Oxygen and Glucose This process is called Cell Respiration Cells which need more energy have more Mitochondria

Ribosomes Make Protein Think BBQ “Rib” (Ribs are MEAT. Meat is PROTEIN!) Can be found attached to the E.R. (Endoplasmic Reticulum) or floating freely in the cytoplasm

Endoplasmic Reticulum System of channels that transports material around the INSIDE of the cell Attached or Near the Nucleus! Two types: Rough ER – has ribosomes attached Smooth ER – no ribosomes

Golgi Packages proteins and ships them OUTSIDE of the cell in packaged vesicles

This is all about Proteins! Remember this… Ribosome Makes ‘em E.R. Takes ‘em Golgi Stacks & Packs This is all about Proteins!

Vacuole A storage area Located in the cytoplasm Used to store water, wastes, food… Located in the cytoplasm Plant cells have one or two large vacuoles Animals cells have many small ones!

Cell Wall Surround PLANT and GREEN ALGAE (and some Bacteria) CELLS Made of Cellulose (a non-living material) Humans CAN NOT DIGEST Cellulose! Protects cell’s contents Supports plant as it grows

Chloroplast FOUND ONLY IN PLANT and GREEN ALGAE CELLS Float in cytoplasm Large, irregular shaped GREEN structure Shown with “stacks” inside Contains Chlorophyll (green pigment) Captures sun’s energy & makes food (glucose) for plant CALLED PHOTOSYNTHESIS!