ChapteChapter 3r 3

CellsCells

CellsCellsSection 3-1 H.W. Pg. 73 quesSection 3-1 H.W. Pg. 73 ques. 1-4. 1-4

What are What are cellscells??-- CellsCells are the smallest unit of living things, and are are the smallest unit of living things, and are

the building blocks of life.the building blocks of life.- All living organisms are made up of cells.All living organisms are made up of cells.- Some organisms are composed of many cells, like Some organisms are composed of many cells, like

humans, animals, trees, and flowers. These humans, animals, trees, and flowers. These multi celledmulti celled organisms can be seen without the organisms can be seen without the use of a microscope.use of a microscope.

- Other organisms are only composed of one Other organisms are only composed of one single cellsingle cell, like bacteria or some algae, and they , like bacteria or some algae, and they can only be seen with the use of a microscope.can only be seen with the use of a microscope.

MicroscopesMicroscopes

A A microscopemicroscope is an instrument used by is an instrument used by scientists to study cells and other scientists to study cells and other microscopic material.microscopic material.

- - Microscopes are very critical to science. Microscopes are very critical to science. They allow us to explore a world that other They allow us to explore a world that other wise was never known.wise was never known.

- - Microscopes use Microscopes use lightlight and and lenseslenses in order in order to magnify the object that you are looking to magnify the object that you are looking at. at.

-- These lenses allow you to see an object at These lenses allow you to see an object at up to 100x its size.up to 100x its size.

History of the CellHistory of the Cell

Why do they call cells, cells?Why do they call cells, cells?- When the first microscope was created When the first microscope was created

the first thing that scientists decided the first thing that scientists decided to look at was a piece of cork, which is to look at was a piece of cork, which is made from trees.made from trees.

- What they saw was a lot of small What they saw was a lot of small boxes that, to them resembled prison boxes that, to them resembled prison cells.cells.

- Hence the name cells.Hence the name cells.

Plant CellPlant Cell

History of the CellHistory of the Cell

However, not all However, not all cells look like cells look like boxes. Only plant boxes. Only plant cells do.cells do.

- Human cells take - Human cells take on many different on many different shapes. As well as shapes. As well as bacterial, fungal bacterial, fungal and algal cells.and algal cells.

Cell CompositionCell Composition

Every cell of an organism, as small as Every cell of an organism, as small as they are , is made up of even small they are , is made up of even small parts.parts.

- These smaller parts that make up a These smaller parts that make up a cell are called cell are called organellesorganelles. What do . What do you think organelle means?you think organelle means?

- It means small organ.It means small organ.

OrganellesOrganelles

Within a cell are Within a cell are many organelles many organelles that perform many that perform many specific functions. specific functions.

- We will also learn We will also learn that there are that there are different organelles different organelles in plant cells than in plant cells than there are in animal there are in animal cells.cells.

Organelles of an animal cellOrganelles of an animal cellpicture on pg. 66picture on pg. 66

The organelles of an animal cell that The organelles of an animal cell that we will explore are:we will explore are:

Cell membrane-Cell membrane- this covers the outside of the cell and this covers the outside of the cell and controls what material enters and leaves the cell.controls what material enters and leaves the cell.

Cytoplasm- Cytoplasm- a gel like liquid that fills the cell. All organelles a gel like liquid that fills the cell. All organelles move around in the cytoplasm and many cell activities move around in the cytoplasm and many cell activities occur here.occur here.

Nucleus-Nucleus- This is the brain or control center of the cell. It This is the brain or control center of the cell. It controls all cell activity.controls all cell activity.

ChromosomesChromosomes- Found in the nucleus and contain our DNA or - Found in the nucleus and contain our DNA or genetic make up.genetic make up.

Mitochondria- Mitochondria- This organelle is responsible for converting This organelle is responsible for converting our food and oxygen to energy, this is called our food and oxygen to energy, this is called Cellular Cellular respirationrespiration. Called the Power house of the cell.. Called the Power house of the cell.

VacuolesVacuoles- These are little storage areas in a cell that hold - These are little storage areas in a cell that hold water, minerals, and food and waste.water, minerals, and food and waste.

Animal CellAnimal Cell

Organelles of a plant CellOrganelles of a plant Cell A plant cell contains all of the organelles that are A plant cell contains all of the organelles that are

present in an animal cell plus two more:present in an animal cell plus two more:

Cell Wall-Cell Wall- This is found in plants, algae, and fungi and This is found in plants, algae, and fungi and it is a thick covering that surrounds the cell it is a thick covering that surrounds the cell membrane. It gives support to the cell and together membrane. It gives support to the cell and together all the cell walls of a plant gives structure to the all the cell walls of a plant gives structure to the whole organism.whole organism.

Chloroplast –Chloroplast – These organelles contain a chemical These organelles contain a chemical called called chlorophyll, chlorophyll, a pigment that traps sunlight a pigment that traps sunlight and converts it into energy. It uses the sun light, and converts it into energy. It uses the sun light, water and CO2 to produce O2. This process is calledwater and CO2 to produce O2. This process is called photosynthesisphotosynthesis..

Plant CellPlant Cell

The different jobs of cellsThe different jobs of cellsSection 3-2 H.W. pg. 81 ques. 1-3 & pg. 86 ques. 1-Section 3-2 H.W. pg. 81 ques. 1-3 & pg. 86 ques. 1-

4, 6-104, 6-10

It is impossible for every cell in your It is impossible for every cell in your body to be able to carry out every body to be able to carry out every job that your body needs to have job that your body needs to have done.done.

That’s why there are many different That’s why there are many different cells in our bodies that all have very cells in our bodies that all have very different, very specific jobs to do.different, very specific jobs to do.

Different types of animal cells and Different types of animal cells and how there shape is related to their how there shape is related to their

function.function. Red Blood Cell- Travel Red Blood Cell- Travel

though your blood though your blood vessels and carries vessels and carries oxygen to tissues all oxygen to tissues all over the body, and over the body, and removes any waste removes any waste products.products.

Have a dimple in the Have a dimple in the middle of them. This middle of them. This dimple is where a dimple is where a molecule of O2 will be molecule of O2 will be carried.carried.

Different types of animal cells and Different types of animal cells and how there shape is related to their how there shape is related to their

function.function. Nerve Cells- They are Nerve Cells- They are

long and shaped like long and shaped like wires in order to carry wires in order to carry electrical impulses electrical impulses around the body.around the body.

Muscle Cells- Are long Muscle Cells- Are long straight fibers that straight fibers that allow us to move our allow us to move our skeleton. They have skeleton. They have many mitochondria. many mitochondria. Why?Why?

- They need a lot of - They need a lot of energy.energy.

Different types of plant cells and Different types of plant cells and how there shape is related to their how there shape is related to their

function.function. Cells of the stem- plant Cells of the stem- plant

stems have many cells stems have many cells that are long and tube that are long and tube shaped. This allows shaped. This allows water from the ground water from the ground to be moved up the to be moved up the plant.plant.

Leaf cells- These cells Leaf cells- These cells are brick shaped and are brick shaped and have many chloroplasts. have many chloroplasts. Why?Why?

- The leaves are exposed - The leaves are exposed to the sunlight and they to the sunlight and they trap it to make food by trap it to make food by photosynthesis.photosynthesis.

Cell organizationCell organization All of these specific cells in your body, as well as All of these specific cells in your body, as well as

in plants, are not just all thrown together. in plants, are not just all thrown together. - You wouldn’t want to have liver tissue in you You wouldn’t want to have liver tissue in you

brain or a leg muscle cell in your stomach.brain or a leg muscle cell in your stomach.- All common cells are grouped together to form All common cells are grouped together to form

specific tissues.specific tissues.- Ex: A lot of cells combine form to make Ex: A lot of cells combine form to make tissuestissues. .

TissuesTissues are groups of similar cells that perform are groups of similar cells that perform similar work. similar work.

-- Tissues would than combine together with Tissues would than combine together with different tissues to form an different tissues to form an organorgan. An . An organ organ is a is a structure made up of two or more different types structure made up of two or more different types of tissue that work together.of tissue that work together.

- Ex: The stomach is an organ made up of muscle Ex: The stomach is an organ made up of muscle tissue, nerve tissue and blood tissue.tissue, nerve tissue and blood tissue.

Cell organizationCell organization

Organs than come together to form organ Organs than come together to form organ systems.systems.

- Ex: the mouth, stomach, intestines, and liver Ex: the mouth, stomach, intestines, and liver are all organs that make up the digestive are all organs that make up the digestive system.system.

- Other systems include the respiratory, Other systems include the respiratory, skeletal, and reproductive systems.skeletal, and reproductive systems.

-- Organs systems then give rise to organisms. Organs systems then give rise to organisms.

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