Bellwork: What would you compare cells to? How does a cell compare to that? A cell is like a __________ because___________. Take 6 mins to complete your work.

Next Generation Science Standards: MS-LS1-1 Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells. MS-LS1-2 Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function.

Objectives: Identify different organelles in a cell. Content Objective: Language Objective: Identify different organelles in a cell. Differentiate between prokaryotic and eukaryotic cells. Differentiate between plant and animal cells. Define cell, organelle, organism, prokaryote, and eukaryote.

Vocabulary Cell: the smallest unit of all living things. Organism: is any living thing. Organelle: a small body in a cell’s cytoplasm that is specialized to perform a specific function. Eukaryote: an organism made up of cells that contain their DNA in a nucleus. Prokaryote: a single-celled organism that does not have a nucleus or membrane-bound organelles.

Cells 8th Grade Lesson

What are thoooooseeeeee?????

A virus attacking a [host] cell.

Red blood cells

Six day old Human Embryo implanting itself.

Sperm on the surface of an egg.

Lung cancer cell

Intestinal Bacteria

What is a cell? All living things are made up of cells. Cells are the smallest unit of life. Robert Hooke was the first person to describe a cell in 1665. Cells mean “little rooms” in Latin.

What is the cell theory? Matthias Schleiden, Theodor Schwann, and Rudolf Virchow led to this important theory. All organisms are made up of one or more cells. The cell is the basic unit of all organisms. All cells come from existing cells.

There are two types of organisms: Unicellular [Prokaryotes] organism is made of one cell. Multicellular [Eukaryotes] organisms are made of more than one cell.

A living thing made of one or more cells. Words to Know Organism A living thing made of one or more cells.

Words to Know Cell Smallest unit of living things that can carry out the basic processes of life.

Structures found in both plant and animal cells. Words to Know Organelles Structures found in both plant and animal cells.

Life Processes Remember the acronym MRS. GERN Movement Respiration Sensitivity Growth Excretion Reproduction Nutrition

Cytoplasm & Organelles Cells Prokaryotic Eukaryotic Alike: Cell membrane DNA Cytoplasm & Organelles Different NO Nucleus No membrane-covered organelles Circular DNA Ex. Bacteria Nucleus Membrane-covered organelles Linear Ex. All other cells

What is DNA? It stands for Deoxyribonucleic Acid It holds all the instructions that tells our body how to develop and function. It’s found in the nucleus as well as in the mitochondria. It’s a molecule made of nucleotides.

What are nucleotides? The nucleotides are adenine, thymine, cytosine, guanine The nucleotides are held by a backbone made of phosphate and deoxyribose. Adenine and Thymine always pair up. Guanine and Cytosine always pair up.

Cell Organelles (plant and animal)

Cell membrane Function: protects the cell from the environment. Allows things to come in and out of the cell. Similar to: our skin

Cytoplasm Function: jelly-like fluid that allows the organelles to float around in. Similar to: blood

Nucleus Function: control center of the cell. Contains DNA/genetic material. Tells the cell how and what to do. Inside the nucleus is the nucleolus which makes ribosomes and sends it out. Similar to: brain

Ribosomes Function: make proteins for the cell Similar to: stomach

Endoplasmic Reticulum Function: Passage way that transport materials. Rough ER (has ribosomes) Smoth ER (no ribosomes) Similar to: digestive system

Golgi Apparatus Function: receives proteins and folds the proteins and add materials to them (lipids or carbohydrates) and sends them to the rest of the cell. Similar to: veins and arteries

Vacuole Function: store materials. Similar to: bladder

Lysosome Function: cleans the cells. Takes in worn out cell parts. They have enzymes that break down the waste. Similar to: kidneys

Mitochondria Function: powerhouse of the cell. Provides energy for the cell. Similar to: muscles

Cytoskeleton Function: maintains the shape of the cell. Made of microfilaments (proteins) and microtubles (tubes) Similar to: skeletal system

Chloroplast (plants only) Function: where photosynthesis happens. Contains chlorophyll which is what makes the plant green.

Cell wall(plants only) Function: found outside the cell membrane. Shape, support and protect the plant cell.

Bacteria

What is a bacteria? They were the first living organisms on Earth. They are prokaryotic, meaning, single-celled organism. They are found in your body and on surfaces. They are found under Kingdom Monera. They are also found under Kingdom Archaebacteria/Eubacteria.

Monerans can be classified into three groups: Eubacteria Cyanobacteria archaebacteria

Eubacteria: They have stiff cell walls and flagella for movement. They are known as “true bacteria” . They are common bacteria.

Cyanobacteria They got its name from the color cyan which is a blue green color. They get their food/energy through photosynthesis. They are aquatic, so they are commonly found in water.

Archaebacteria They are known as “ancient bacteria”. They are found in extreme environment such as hot boiling water and thermal vents with no oxygen or highly acidic environments.

Some exist as single cells, others cluster together What do they look like? Three basic shapes Rod shaped called bacilli (buh-sill-eye) Round shaped called cocci (cox-eye) Spiral shaped Some exist as single cells, others cluster together

Bacilli Cocci Cluster of cocci Spiral

How do bacteria reproduce? They reproduce asexually (they do not need a partner). Specifically through binary fission. Unlike humans, they grow in size from child to adult and reproduce sexually.

How do bacteria reproduce? Through binary fission, they make copies of themselves by dividing in half. Genetic information in the parent cell is passed to each new daughter cells.

Some make their food from sunlight, cyanobacteria. How do bacteria eat? Some make their food from sunlight, cyanobacteria. Some are decomposers (they break down left-overs) Some are pathogens (attack other living things).

Bacteria that make you sick. Why do they make you sick? What are pathogens? Bacteria that make you sick. Why do they make you sick? To get food they need to survive and reproduce. How do they make you sick? They produce toxins that result in fever, headache, vomiting, diarrhea, and destroy body tissue.

Where do you get pathogens? Contact with people who are sick. direct or indirect Food, water, or other surfaces that are contaminated.

Are all bacteria pathogens? No, most are harmless Some are helpful Lactobacillus: make cheese, yogurt, and buttermilk and produces vitamins in your intestine. Pediococcus: found in pepperoni, salami, and other sausages.

A Closer Look – Helpful Bacteria www.bioweb.usu.edu Pediococcus - used in production of fermented meats Lactobacillus casei – found in human intestines and mouth to improve digestion Leuconostoc cremoris – used in the production of buttermilk and sour cream Lactobacillus bulgaricus – used in the production of yogurt Hands On: Real World Lessons for Middle School Classrooms© University of Tennessee, Knoxville 2009

What are some common pathogens? E. coli O157:H7 Pathogenic E. coli (like O157:H7) Found in ground beef, contaminated fruits and vegetables Salmonella Found in raw meats, poultry, eggs, sprouts, fruit and vegetables Listeria Found in deli foods, lunch meats, smoked fish and vegetables Salmonella Listeria

Examples of Pathogens Salmonella E. coli O157:H7 What shape are these bacteria? Cocci, bacilli, or spiral? Staphylococcus aureus Campylobacter jejuni Hands On: Real World Lessons for Middle School Classrooms© University of Tennessee, Knoxville 2009

Ways to avoid pathogens? Wash your hands Cook food thoroughly Store food properly