• How big?• http://www.cellsalive.com/howbig.htm

Cells Alive

Objectives:

• Microscopes are used correctly to observe living cells.

Cells •basic units of structure and

function in living things. • (all living things are made

of cells) •1 cm of your skin’s surface

contains 100,000 cells too tiny to see.

Structure vs. Function

• What it What it does.

Appears to look What it runs.

Like. How it is Why it is set up

Organized. The way it is.

Structure vs. Function

Structure vs. Function

Structure and Function in people

Structure vs. Function

Structure: Cells have different structures

and are made differently

Function: Because they do different

things!

FIRST SIGHTINGS OF CELLS

•Microscope—an instrument that makes small objects look larger.

FIRST SIGHTINGS OF CELLS

• The 1590 invention of microscope allowed people to look at very small objects. The microscope made it possible for people to discover and learn about cells.

                                                      

•       Simple microscope—contains one lens that helps to focus light                                                   

•       Compound microscope—a light microscope that has more than one lens.

Robert Hooke a. One of the first people to observe cells. In 1663 Hooke

observed a small piece of cork with a compound microscope that he built. Cork is made from the bark of the cork oak tree, and is made up of cells that are no longer alive. He saw tiny “rectangular little rooms” that he called cells. He found that one centimeter of cork had over a thousand cells.

Anton van Leeuwenhoek • a Dutch businessman and amateur scientists

made his own lenses to construct a simple microscope. He looked at water from a pond and found many one-celled organisms which he called “animalcules” meaning small animals. Also looked at scrapings from teeth and was the first person to see the tiny single-celled organisms that are now called bacteria. Many people began to study cells after his findings.

• PASS Strand:Structure and Function in Living Systems

• Objectives: (What we will be talking/ learning about)

Microscopes are Used correctly to observe living cells.

Cells are the building blocks of all organisms (both plants and animals).Local extension: The cell theory states:

1. All living things are made up of cells. 2. Cells are the basic units of structure and

function in all living things. 3.Living cells come only from other living cells.

THE CELL THEORY

• Microscopes led to the discovery that all living things are made up of cells.

– Schleiden (shly-dun)—scientists who discovered that plants are made up of cells.

– Schwann—scientists who discovered that all animals are made up of cells. All living things are made up of cells.

– Virchow—(fur koh) new cells are only formed from existing cells. All cells come from other cells.

–These discoveries led to the CELL THEORY. The CELL THEORY is a widely accepted explanation of the relationship between cells and living things It states• All living things are composed of cells

• Cells are the basic unit of structure and function in living things

• All cells are produced from other cells.

How A Light Microscope Works

• Microscopes use lenses to make smaller objects look larger. Microscopes must include magnification and resolution.

Magnification—the ability to make things look larger than they are.

• Lens—the lens or lenses in a light microscope magnify an object by bending the light that passes through them.

• Convex lens—curved lens. Center is thicker than edges.

Magnification

• Compound microscopes—use more than one lens, so magnify more than simple microscopes.

• Total magnification is equal to the magnifications of the two lenses multiplied together.

Resolution—is the ability to clearly distinguish the individual parts of an

object. It helps the image look “sharper”, “more clear” or “being able to see fine

detail”

ELECTRON MICROSCOPES– Hooke, Leeuwenhoek and others all

used light microscopes.

– 1930s electron microscope was invented.

• Use a beam of electrons instead of light to examine a specimen.

• Resolution is much better than light microscopes.

• Continue to learn about the structure and function of cell

Cells and Heredity

• “Looking Inside of Cells”

• PASS Strand:Structure and Function in Living Systems

• Objectives:Specialized structures perform

specific functions at all levels of complexity (e.g., leaves on trees and wings on birds).

OrganellesOrganelles

•objects inside a cell, which carry out specific functions within the cell.

Cell Wall • a rigid layer of nonliving material that

surrounds the cells of plants and some other organisms

• Make of touch, yet flexible material called cellulose

• Helps to protect and support the cell• Water and oxygen can pass through the cell

wall • Ex. Screen on a window

Cell Membrane Located just inside the cell wall in plants.

Animals, it is the outside boundary that separates cells from its environment.

Nucleus

• Acts as the “brain” of the cell. It directs all the cell’s activities.

Organelles in the Cytoplasm • Cytoplasm

—                                                       • area between the cell membrane

and nucleus.                                                     • Gel-like fluid in which many

organelles are found.

Mitochondria • Rod shaped structures• The “powerhouse” of the cell• Produce most of the energy the

cell needs to carry out its functions.

Endoplasmic Reticulum • Maze of passageways• Carry proteins and other materials

from one part of the cell to another.

Ribosomes

•Grain-like bodies attached to the outside of the endoplasmic reticulum

•Also found floating in the cytoplasm.

•Factories to produce proteins.

Golgi Bodies

• Flattened collection of sacs and tubes

• Cells “mail room”• Receive proteins and other

materials from the endoplasmic reticulum, package them, and send them off to other parts of the cell.

Chloroplasts • Large green structures floating in

cytoplasm. • Capture energy from sunlight and

use it to produce food for the cell.• Give plants green color.

Vacuoles

• Large, round, water-filled sac floating in the cytoplasm.

• Storage area of the cell.• Plant cells (mostly) have 1 large

vacuole.• Animal cells may or may not have

one.

Lysosomes • Small round structures that contain

chemicals that break down large food particles into smaller ones.

• Recycle old cell parts so they can be used again.

Bacterial Cells • Smaller than plant or

animal cells• Has a cell wall and cell

membrane • Has no nucleus• Genetic material (looks

like waded string) is found in cytoplasm

• Contain ribosomes, but no other organelles

Bacterial cells

Specialized Cells

• Cells are suited to the functions they carry out.

• Ex. Blood cells look different than nerve cells and have different jobs.

Lets review the differences between plant and animal cells

Cell No 5 Song

• (and there’s an easy way to remember it!)

TEXTBOOK: Human Biology and Health

“How the Body is Organized”

• PASS Strand:Structure and Function in Living Systems

• Objectives: Living systems are organized by levels

of complexity, i.e. cells, tissues, organs, and organ systems, organisms, and ecosystems.)

• The levels of organization in the human body consist of cells, tissues, organs, and organ systems.

• Organ systems together make organisms. Organisms create ecosystems.

CELLS

LEVELS OF ORGANIZATION

Cells--basic unit of structure and function in a living thing.

• Unicellular—organism which only has one cell

• Multicellular—complex organism made up of several cells

Tissues

• a group of similar cells that perform the same function. Perform a specific job.

Tissues

• a.     Muscle tissue—cells can contract or shorten

• b.     Nerve tissue—carries messages between brain and body

• c.      Connective tissue—Support for body, connects all parts of body

d. Epithelial tissue—Covers the surfaces of your body, inside and out

Organs • a structure that is composed of

different kinds of tissue. Performs a specific job.

Organs

• Heart—is an organ. Function: pumps blood through your body. Is made up pf 4 kinds of tissue. Each helps with the overall job.

• Kidneys-- two bean-shaped organs. Helps keep water volume in body constant. Helps remove wastes from body and helps regulate blood pressure

• Skin—largest organ. Covers and protects body.

Organ System

• a group of organs that work together to perform a major function

Circulatory—carries materials to body cells, carries wastes away from body cells helps fight disease.

Organ System • Digestive—

takes food into the body, breaks food down, and absorbs the digestive materials

Organ System

• Immune—

Fights

disease

Organ System • Muscular—

Enables the body to move, moves food through the digestive system, keeps the heart beating

Organ System • Nervous—

detects and interprets information from the environment outside the body and from within the body, controls most body functions

Organ System

• Respiratory—Takes oxygen into the body and eliminates carbon dioxide

Organ System • Skeletal—

Supports the body, protects it, and works with muscles to allow movement, makes blood cells and stores some materials

Examples: LEVELS OF ORGANIZATION • 1. Bone cell— responsible for bone

growth and repair.• 2. Bone tissue— consists of living cells

that are separated from one another by a hard non-living material that gives bones their strength.

• 3. Bone organ— Ex. Thigh bone or femur consists of different kinds of tissues. (also contains blood and nerve tissue)

• 4. Organ system— Skeletal system. Made up of over 200 bones. Includes cartilage and ligaments.

Organism• Organ systems

come together to produce a living creature. An individual form of life, such as a plant, animal, bacterium, protist, or fungus;

Ecosystem

• A community of plants, ___________, and microorganisms that are linked by energy and nutrient flows and that interact with each other and with the physical environment.

Interdependence

• depending on other things to get a job done. Working together.

Osmosis

Diffusion

TEXTBOOK: HUMAN BIOLOGY AND HEATH

“Keeping the Body in Balance”

• PASS Strand:4. Behavior and Regulations

• Objectives: B. Living organisms strive to maintain a

constant internal environment (i.e., temperature regulation).Local extension: Stable internal conditions are related through homeostasis.

Homeostasis• the body’s tendency

to maintain an internal balance. Process by which an organism’s internal environment is kept stable in spite of the changes to the external environment.

Stress “threatening, challenging or disturbing

events” • a.      More blood goes to brain• b.      Hearing ability increases• c.      Sweating increases• d.      Muscles tense• e.      Pupils widen to take in more light• f.        Heart rate increases• g.      Digestive system slows

Being startledBeing startled “ “fight or fight or flightflight “

•Respiratory system provides Respiratory system provides more oxygenmore oxygen

• Muscular and Skeletal system are Muscular and Skeletal system are ready for fight or flightready for fight or flight

Water Balance

•Thirst•Urination•Sweat•Tears

4. Temperature • A. Endothermic

organisms— an

animal whose body controls and regulates its temperature by controlling the internal heat it produces. Temperature does not change much

Endothermic organisms• Homeostasis—controls its own

environment• Mammals and birds• It is hot outside, your temperature

is about 98.6 F• It is snowing outside, your

temperature is about 98.6 F

Temperature • Ectothermic

organisms— an animal whose body does not produce much internal heat. Its body temperature changes depending on the temperature of its environment.

Ectothermic organisms

• Fishes, amphibians and reptiles

• A turtle lies in the sun, its body temperature rises

• A turtle lies in the snow, its body temperature lessens

A negative feedback loop

• works in the opposite direction from what it is trying to accomplish. An example of a negative feedback loop involved in homeostasis is maintenance of body temperature.

• As a person’s body gets too hot, (s)he begins to sweat in an attempt to lower the temperature. If someone’s body is too cool,(s)he will begin to shiver in an attempt to increase the temperature. Example: Air conditioning

Necessary Components of a Homeostatic System

• Receptor

• Control Center

• Effector

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Homeostatic Mechanism

• Negative-Feedback Regulation– The homeostatic mechanism

• Positive-Feedback Regulation– Birthing contractions

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-cells release glucagon stimulate glycogen breakdown and gluconeogenesis

-cells release insulin stimulate glucose uptake by peripheral tissues

Glucose HomeostasisLower Blood

Glucose

Higher Blood GlucoseFood

Between meals