Welcome to the 7th Grade Science Exam Review

CELLS I can describe the function of a cell as a whole. I can identify and give the function of the organelles (structures in the cytoplasm) of both a plant and an animal cell. I can give the differences between a eukaryotic and a prokaryotic cell. I can explain the main differences between plant and animal cells. I can explain that cells make up tissues, tissues make up organs, and organs make up larger organisms. I can explain that all living things are made of one or more cells and that there are different types of cells.

Animal Cell Cell Membrane Nucleus Cytoplasm Mitochondria Endoplasmic Reticulum Lysosome Ribosomes Golgi Bodies

Plant Cell Endoplasmic Reticulum Nucleus Mitochondria Vacuole Golgi Bodies Chloroplast

Cell Theory Cells are the basic unit of life All living things are made of cells Cells come from other cells

Cells are… Definition: The basic unit of life Cells produce tissues  Tissues produce organs  Organs produce organ systems  Organs systems produce organisms

What is the difference between a single cell and cells working together? Cell Specialization by Brainpop Single Cells do everything by themselves; Cells in tissues and organs divide up the work!

Prokaryotic vs. Eukaryotic Eukaryotic Cells: Have a TRUE NUCLEUS and DNA Example: all cells in your body Prokaryotic Cells: NO NUCLEUS Example: Bacteria

Gel-like material inside cells FUNCTION: Gel-like material inside cells CELL PART: CYTOPLASM

“GATE KEEPER”—Controls what goes in and out FUNCTION: “GATE KEEPER”—Controls what goes in and out CELL PART: CELL MEMBRANE

Directs all cell activities FUNCTION: Directs all cell activities CELL PART: NUCLEUS With the electron microscope

Pathway for moving materials through cell FUNCTION: Pathway for moving materials through cell (the “express-way”) CELL PART: Endoplasmic Reticulum or ER

FUNCTION: CELL PART: Make protein! RIBOSOMES Under the electron microscope: A simple diagram Under the electron microscope:

Releases energy in the cell; the “powerhouse” FUNCTION: Releases energy in the cell; the “powerhouse” CELL PART: MITOCHONDRIA Under the electron microscope:

Converts sunlight into cell energy FUNCTION: Converts sunlight into cell energy (Found in plants ONLY!) CELL PART: CHLOROPLAST Under the microscope

The outer structure in plant cells; made of cellulose FUNCTION: The outer structure in plant cells; made of cellulose CELL PART: CELL WALL Under the microscope

Store water, food, and waste products; FUNCTION: Store water, food, and waste products; Very large in plant cells, small in animal cells CELL PART: VACUOLES Under the microscope

Nicknamed “UPS”—Packages & secrete substances made inside the cell FUNCTION: Nicknamed “UPS”—Packages & secrete substances made inside the cell CELL PART: GOLGI BODIES Under the microscope

FUNCTION: CELL PART: Digests cell wastes LYSOSOMES “garbage disposal” Under the microscope

What are the two parts that plant cells have that animal cells do not have? Cell Walls Chloroplasts

Animal and Plant Cells

Cellular Respiration (breaking down food) We need Oxygen and sugar (glucose) to get energy for our cells to do things. As a byproduct, CO2 (carbon dioxide) and H2O (water) are given off. We breathe in O2, breathe out CO2

Cellular Respiration (breaking down food) glucose/sugar ATP Reactants Products (what goes in) (What comes out) Cellular respiration takes place in the mitochondria. H20 + CO2+ E O2 + C6H12O6

Photosynthesis Plants can make their own food using sunlight as energy. What organelle do plants use to do this? Chloroplast Chlorophyll It’s what makes plants GREEN

Photosynthesis Plants absorb water through their roots & CO2 through their leaves. Plants use sunlight to power this transformation into food. Plants store their food in the form of sugars (glucose).

Photosynthesis H20 + CO2+ E O2 + C6H12O6 glucose/sugar Reactants Products (what goes in) (What comes out) H20 + CO2+ E O2 + C6H12O6

Photosynthesis As a byproduct, plants give off Oxygen We consume/eat plants and need oxygen they make. We are called CONSUMERS. This why plants and all photosynthetic organisms are called PRODUCERS.

Osmosis and Diffusion What does “concentration” mean? For example: the concentration of salt in sea water. Concentration means: The number of “particles” in a given space. Which is more concentrated? OR

Diffusion Diffusion is the natural movement of any molecule from high concentration (where there’s lots of them) to low concentration (where there’s not as much) until they are equally spread out.

Osmosis Diffusion of water from high to low concentration

Osmosis

Why is this important to cells? Diffusion and Osmosis is how things like oxygen, food, and water get transported into and out of cells.

Diffusion is a slow process because it relies on the random movement of atoms and molecules.

Egg Lab: Background Hypotonic: it causes it to swells up (think Hypo = Hippo) Hypertonic: it causes it to shrivel up (Think hyper skinny kid)