Cells – What are they?

Overview 1. Cells are the basic unit of structure and function in living things. 2. The structure of living things is determined by how the cells are arranged

Overview of Cells 3. Functions that cells perform in living things… ◦ Obtain oxygen ◦ Get rid of waste 4. Your hand is made up of more than 100,000 cells. Why can you not see them? MICROSCOPIC!

Overview of Cells 5. did no one know about cells until 1590? The microscope was not invented yet! 6. Microscope: Instrument used to make small object appear larger.

7. Simple versus Compound Simple Microscope One lens Compound Microscope More than one lens used

Overview of Cells 8. Who was the first one to observe cells? Robert Hooke 9. Cells literally means “tiny rooms”

Robert Hooke #10: Robert Hooke used the term “cells” (small rooms) because he thought they looked like the small rooms that monks lived in. Like jail cells – small rooms on top of each other

Cork Cells When he looked at cork…

Anton van Leeuwenhoek 11. He looked at  Lake Water  Scraping from teeth and gums  Water from rain gutters

Development of the Cell Theory 13. Scientists who developed the cell theory:  Schwann  Schleiden  Virchow

Cell Theory 14. What is the cell theory?  Widely accepted explanation of the relationship between cells and living things.

15. Cell Theory States: 1. All living things are composed of cells 2. Cells are the basic unit of structure and function in living things 3. All cells are produced from other cells

16. When does the theory hold true? The cell theory holds true no matter how big or small a living thing is.

Microscopes There are two types of microscope ◦ Light ◦ Electron

17. Properties of Microscopes Magnification: The process of enlarging something in appearance Resolution: Ability to distinguish the individual parts of a object

18. Types of Microscopes Light: Use lenses to bend light and magnify an object

18. Types of Microscopes Electron: Uses beams of electrons instead of light to magnify an image

Looking Inside Cells

Inside Cells 19. Inside cells are even smaller structures called organelles. 20. Organelles carry out specific functions within a cell.  Just like your stomach, lungs and hearts all have specific functions!

21. Organelles: Entering the Cell Cell Wall Rigid structure that surrounds a plant cell and gives it shape Cell Membrane Protects cell and regulates what substances enter and leave a cell Similar to our Skin! Protection!

21. Nucleus – Control Center Nuclear Envelope Surrounds and protects the nucleus Similar to our ribcage! Nucleolus Where ribosomes are made Chromatin Contain genetic material which are instructions for directing the cells function

21. Organelles in the Cytoplasm Cytoplasm: The material within a cell apart from the nucleus Mitochondria: Rod-Shaped cell structures that convert energy in food molecules to energy the cell can use to carry out its functions Endoplasmic Reticulum: A cell structure that forms passageways in which proteins and other materials can be carried. Ribosomes: A small grain-like structure in the cytoplasm of a cell where proteins are made.

21. Organelles in the Cytoplasm Golgi Bodies: A structure that receives proteins and other newly formed materials from the ER, packages them and distributes them Chloroplasts: A structure in the cells of plants that captures energy from sunlight to use to make food

21. Cell Organelles Vacuoles: Storage units in the cell Lysosomes: A small, round cell structure containing chemicals that break down large food particles into smaller ones

Cell City

Endoplasmic Reticulum / Golgi Bodies = Transport company They transfer materials from one part of the cell to another Package materials and distribute them

Cell City Ribosomes = Construction site They build structures (Proteins)

Cell City Mitochondria = Power Plant “Powerhouse” of the cell Provides power or energy for the cell to run

Cell City Chloroplasts = Food Producing Plant Makes food (Using photosynthesis) Kitchen!

Cell City Vacuole = Storage Units Stores food & water Closet!

Cell City Lysosomes = Recycling and Waste Plant Breaks down large molecules into smaller ones that are easier for the cell to use

Cell City Nucleus = City Hall Boss of the cell Has instructions for everything that is going on in the cell

Cell City Cell Membrane / Cell Wall = Main Gate or Fence Surrounds and protects the cell Regulates what goes in and out of the cell Security

Eukaryotes vs Prokaryotes Eukaryotes: Organisms who’s cells have nuclei (more advanced) Prokaryotes: Organisms who’s cells LACK nuclei.

Chemical Compounds in Cells 38. Element: Any substance that cannot be broken down into a simpler substance (Made up of only one type of atom)

Chemical Compounds in Cells 39. Compound: Two or more elements that are chemically combined (Made up of two or more types of atoms)

41. Chemical Reactions without water? Cells are mostly made out WATER! Without water your cells would not function properly

42. Organic vs Inorganic Any compound that contains the element Carbon (C) is called an organic compound

43. Organic Compounds A. Carbohydrates B. Lipids C. Proteins D. Nucleic Acids

Cell Environment 47. What part of the cell controls what goes in and out of the cell? ◦ Cell Membrane! ◦ Both plant and animal cells!

48. Selectively Permeable Some substances are allowed to pass through the cell membrane while others are not

49. Can move in or out of the cell by three methods: A. Diffusion B. Osmosis C. Active Transport

50. Diffusion Main method of movement Process by which molecules move from an area of higher concentration to an area of lower concentration

51. Diffusion Continued Molecules are always moving More movement = more bumping into each other More collisions will cause the molecules to move apart from each other

52. Osmosis vs Diffusion Osmosis is the diffusion of water! 53. Cells cannot function properly without water so almost all cellular processes depend on osmosis

Cell Division

54. What is the cell cycle? The process by which cells divide and make more of themselves

Cell Division Cell Division is actually made up of 3 parts ◦ Interphase ◦ Mitosis ◦ Cytokinesis

55. Stage 1 - Interphase Cell grows and makes a copy of its DNA

55. Stage 2 - Mitosis One copy of DNA is distributed to each daughter cell

55. Stage 3 - Cytokinesis Cytoplasm divides and organelles split between the cells

56. Cytokinesis in Plant and Animal cells A. Animal cells: Cell membrane pinches together and cytoplasm divides into two cells (daughter cells) B. A new membrane forms across the middle and gradually develops into a new cell membrane.

57. Mitosis (Second Step of Cell Division) Prophase ◦ Chromatin condense to form chromosomes Metaphase ◦ Chromosomes line up at middle of cell

Telophase ◦ Chromosomes begin to stretch out and lose their rod like appearance Anaphase  Chromosomes spite and move to opposite end of cells 57. Mitosis (Second Step of Cell Division)