Homeostasis The goal of living things is to maintain homeostasis (a dynamic equilibrium, health, internal balance) All life functions interact in order to maintain this!

Metabolism A combination of ALL the chemical reactions occurring in an organism Refers to ALL 8 life processes/metabolic functions!

The Cell Theory

The discovery of cells and their structure is linked to the development of the magnifying lenses, particularly the microscope in the late 1600’s Many scientists of the time recognized the importance of cells as building blocks of living tissue. But not until 1838-39 did the general statement of "cell theory" receive general acceptance Learn Biology

All living things are composed of cells! The cells are the basic unit of structure and function in all living things! Cells arise from pre-existing cells!

Exceptions and Problems with the Cell Theory The Cell Theory does NOT explain… Where did the first cell come from? What is a virus? It has a non-cellular structure and can only REPRODUCE within a host cell! Why do mitochondria and chloroplasts have their own DNA? How did it get there?

Chloroplast Mitochondria

Viruses Are Viruses Alive? - YouTube

Categorizing Cells Brainpop Eukaryotes: complex cells with nuclei and many cell organelles (Animals, plants, fungi and protists) YOU are a Eukaryote! Prokaryotes: simple cells with no nuclear membrane and few organelles (bacteria)

5 10 7 1 8 6 2 4 3 11b 11a 9 LYSOSOME CYTOPLASM CENTRIOLES CELL MEMBRANE 8 GOLGI BODY 6 NUCLEOLUS 2 NUCLEUS/ CHROMOSOMES 4 RIBOSOME 3 MITOCHINDRIA 11b ROUGH E.R. NUCLEAR MEMBRANE 11a SMOOTH ENDOPLASMIC RETICULUM 9 VACUOLE

Nucleolus Nucleus/Chromosomes Golgi Body Chloroplast Nuclear Membrane Smooth ER Cell wall Cell Membrane Rough ER Mitochondrion Large central vacuole Ribosome Cytoplasm

Only plant cells have… Cell Wall provides structure and support for plants and algae Chloroplasts site for photosynthesis (nutrition in plants and algae) Large Central Vacuole needed to maintain turgor pressure They do NOT have centrioles!!!

1. Cell (Plasma) Membrane Regulates the movement of materials into and out of the cell “selectively permeable” Contains Receptors

2. Nucleus Contains the genetic information (chromosomes, genes, DNA) Controls and directs the cell’s activities

3. Mitochondria Site of cellular respiration Produces ENERGY (ATP!) “the mighty mitochondria!!!”

4. Ribosomes Site of protein synthesis (the main job of the cell) - building proteins out of amino acids)

5. Cytoplasm Watery jellylike medium Circulates materials around the cell (cyclosis) Site for many chemical reactions

6. Nucleolus Builds Ribosomes which make proteins Contains messenger RNA

7. Centrioles Used in Cell division (mitosis) Only in animal cells

8. Golgi Complex (Apparatus) Packages Proteins made by ribosomes Sends proteins to final destination either in the cell membrane or outside of the cell

9. Lysosome Contain enzymes Fuse w/food vacuoles to help with digestion “Lyse” rhymes with “slice” “lysol” breaks apart bacterial cells

10. Vacuole Storage of water, food, enzymes, waste Contractile (large central) vacuole helps maintain water balance in plants (think of a vacuum storing waste)

11. Endoplasmic Reticulum Transport, storage, and synthesis of substances (mainly proteins) within the cell

Smooth Endoplasmic Reticulum Storage and creation of steroids

Rough Endoplasmic Reticulum Covered in ribosomes (rough) Takes the proteins and send them to the golgi complex

12. Chloroplast Site for photosynthesis in plants!

13. Cell Wall Provides structural support in plant and bacterial cell!

14. Microtubules Form the cytoskeleton Gives cell its structure Allows movement of chromosomes and other organelles inside cell

Nuclear Membrane Surrounds the nucleus allowing certain materials to enter and leave (RNA)

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The Cell Membrane

Functions of the Cell Membrane To REGULATE the movement of molecules from one side of the membrane to another To recognize chemical signals and communicate with other cells using RECEPTORS!

Cell Membrane Structure “Fluid-Mosaic” model A double layer of lipids (fats) with many carrier proteins and receptors imbedded in them Carrier Proteins – transports larger molecules into and out of the cell Receptors – aid in cell communication as they pick up and receive chemical signals

Materials that CAN pass through the membrane are SMALL: Small enough to move through the lipids: Carbon dioxide (CO2) Oxygen (O2) Water (H2O) Larger, but can use the protein channels to get through: Sugars (glucose – C6H12O6) Amino acids

Materials that CANNOT pass through the membrane: Large molecules like starch

Types of movement across the membrane Brainpop Types of movement across the membrane The Plasma Membrane - YouTube 1) Passive Transport (Diffusion) DOES NOT require ENERGY Moves molecules from high to low concentration (more to less) Osmosis = the diffusion of water

Moves molecules from low to high concentration (less to more) 2) Active Transport Requires ENERGY! Moves molecules from low to high concentration (less to more) Examples: Endocytosis & Exocytosis - YouTube

Movement Across the Membrane When do the molecules move? When there is an unequal amount of solute and water on either side of a membrane

1) Isotonic Solution when concentration of water and solute are equal on both sides of the membrane Nothing moves!

2) Hypertonic Solution (high solute) There is more solute outside the cell, so water moves OUT of the cell, causing the cell to shrivel

3) Hypotonic Solution (low solute) There is less solute outside the cell (more water), so water moves INTO the cell, causing the cell to swell Think of hypo = hippo = fat