The Cell and its Organelles Use this presentation in conjunction with the Cell Organelle note-taking worksheet. Run through the entire presentation before using it in class so that you know what’s coming next! It helps to print the outline and notes to have with you while presenting so that there are no surprises. –JessB.org

Scientists of Cells Hooke  viewed cork; coined the term “cells” van Leeuwenhoek  first to view cells under the microscope Schleiden  plants made of cells Schwann  animals made of cells Virchow  new cells only come from division of other cells ALL THESE SCIENTISTS LED TO THE DEVELOPMENT OF THE CELL THEORY!

Cell Theory All living things are composed of cells Cells are the basic units of structure and function in living things New cells are produced from existing cells

Cell Categories Prokaryotes Eukaryotes (YOU!) no membrane bound organelles genetic material not in the nucleus Cell membrane Small Eukaryotes (YOU!) Have organelles Genetic material contained in nucleus Large

Categories of cells Prokaryotes Eukaryotes Bacteria animal cells plant cells Eukaryotes

Cells and The Work of Life gas exchange: O2 in vs. CO2 out take in & digest food make energy ATP build molecules proteins, carbs, fats, nucleic acids remove wastes control internal conditions respond to external environment What are they responding to? build more cells growth, repair, reproduction & development ATP

Cell Organelles Carry out specialized functions within the cell Lots of different ones found in eukaryotic cells Cytoplasm is a thick, liquid residing between the cell membrane holding all living material inside the cell doesn't contain the nucleus. You may or may not wish to distinguish between cytosol and cytoplasm. The correct use of each term is shown here. Most high school textbooks, however, use the word “cytoplasm” to mean “cytosol.”

Cytoskeleton Acts as skeleton and muscle Provides shape and structure Helps the cell with movement Microtubules Microfilaments Actin, also found in muscle cells, mainly help maintain cell shape in their cytoskeletal role. Microtubules mostly move organelles around the cell. Intermediate filaments also provide structural support.

Cell Wall Found in plant and bacterial cells Rigid, protective and supportive barrier Located outside of the cell membrane Porous Made from fibers of carbs and proteins Plant Cell Walls are made from Cellulose Plasmodesmata: holes or channels in the cell wall that allow for transport/communication This is an actual microscopic image. Explain that the colors are added digitally to enhance the different parts.

1st MAJOR FUNCTION: CELLS NEED TO MAKE ENERGY! To fuel daily life & growth, the cell must… take in food & digest it take in oxygen (O2) make ATP (energy) remove waste Organelles that do this work… cell membrane vacuoles lysosomes mitochondria ATP

Cell Membrane Boundary of the cell Made of a phospholipid bilayer Emphasize word parts here: phospho= phosphate head; lipid= fatty acid tail bi= 2

Cell membrane (ctd.) separates cell from outside environment phosphate “head” Function separates cell from outside environment controls what enters or leaves cell O2, CO2, food, H2O, nutrients, waste recognizes signals from other cells allows communication between cells Structure Double layer of fat phospholipid bilayer Protein molecules (50%) Receptor proteins Structural proteins Protein channels carb chains ID cards lipid “tail”

Lysosomes Garbage disposal of the cell  THEY GET RID OF THE CELL JUNK Contain digestive enzymes that break down wastes and food Food needs to be broken down into useable forms Breakdown organelles that aren’t functioning properly Students should recognize the shapes of the Golgi and ER even if they cannot read the captions.

Vacuoles Large central vacuole usually in plant cells Many smaller vacuoles in animal cells Storage container for water, food, enzymes, wastes, pigments, etc. The image is 2D, so it must have been a light microscope or TEM. If the cell is very tiny, then a TEM was used. Otherwise, a strong light microscope could have captured this image.

plant cells animal cells Food & water storage food vacuole central vacuole contractile vacuole

Mitochondria Nickname: “Powerhouse of the cell” Function: Convert chemical energy stored in food into compounds that are usable by the cell Cellular respiration occurs here Bound by a double membrane Has its own DNA, ribosomes, and can make its own protein! Explain that this diagram shows the mitochondria cut open to reveal the internal membranes.

Mitochondria are in both cells!! animal cells plant cells mitochondria

Chloroplast Found only in plant cells Contains the green pigment chlorophyll Site of food (glucose) production Bound by a double membrane Chloroplasts absorb light, which is the catalyst for photosynthesis.

Second important function cells need to make proteins! Making proteins to run daily life & growth, the cell must… read genes (DNA) build proteins structural proteins (muscle fibers, hair, skin, claws) enzymes (speed up chemical reactions) signals (hormones) & receptors organelles that do this work nucleus ribosomes endoplasmic reticulum (ER) Golgi apparatus

Nucleus Function: Control center of the cell Contains DNA Contains instructions for making protein Surrounded by a double membrane Usually only one per cell Cells with more than one nucleus include muscle cells and liver cells, largely because of the massive volume of cytoplasm and number of organelles that need controlling.

Ribosome Small particles of RNA and protein Function: Site of protein synthesis Found attached to rough ER or floating free in cytoplasm Produced in a part of the nucleus called the nucleolus A polypeptide is a chain of amino acids. In this diagram, you can see the ribosome is making a polypeptide, also known as a protein.

Endoplasmic Reticulum Nickname: “ER” Connected to nuclear membrane “Highway of the cell” Rough ER: studded with ribosomes; it makes proteins Smooth ER: no ribosomes; functions in detoxification; it makes lipids! It’s not necessary that the students can read the labels here; just point out the black dots are ribosomes.

Golgi Apparatus Function: Stores, modifies and packages proteins Nickname: Post office of the cell Molecules transported to and from the Golgi by means of vesicles AKA Golgi Complex. It is not necessary that the students read the labels, this diagram gives them a general idea of the Golgi’s shape.

THIRD IMPORTANT JOB! Cells need to make more cells! To replace, repair & grow, the cell must… copy their DNA make extra organelles divide the new DNA & new organelles between 2 new “daughter” cells Organelles that do this work Nucleus Microtubules Centrioles

Microtubules Made up of proteins known as tubulins Important in cell division mitotic spindle  separates chromosomes

Centriole Help coordinate cell division Found only in animal cells One pair in each cell Made of microtubules Microtubules are also part of the cytoskeleton.