organisms support the essential functions of life ... cell theory all organisms are made up of one...
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Cell Structure
Standard 7.L.3 The student will demonstrate an understanding of how the levels of organization within
organisms support the essential functions of life.
Lesson Standard 7.L.3A.1 Obtain and communicate information to support claims that (1) organisms are made of one or more cells, (2) cells are the basic unit of structure and function of organisms, and (3) cells come only from existing cells
The History of Viewing Cells
● The first microscope was made in the late 1500’s. It was two magnifying glasses put together in a tube.
● Antonie van Leeuwenhoek made a simple microscope with a tiny glass bead for a lens.
● THINK ABOUT IT: What kind of microscopes do we use in lab?
Development of the Cell Theory
Cell Theory: the summary of ideas that says:
1) All organisms are made up of one or more cells
2) The cell is the basic unit of organization
3) All cells come from cells that already exist
Development of the Cell Theory - Timeline
● 1665: Robert Hooke looked at a thin slice of cork under a microscope. He saw tiny empty boxes, which he named cells.
● 1830: Matthias Schleiden studied plants under a microscope. He concluded that all plants are made of cells.
Development of the Cell Theory - Timeline
● Theodor Schwann studied animals under a microscope. He concluded that all animals are made of cells.
● Schleiden and Schwann came to the conclusion that all living things are made of cells.
● Rudolf Virchow made a hypothesis that cells divide to form new cells. Cells come from a cell that already existed.
Robert Hooke
Cells means “little rooms” in Latin
Schleiden & Schwann
Plant cell
Animal cell
Rudolf Virchow
The Cell Theory All organisms are made up of one or more cells.
An organism can be one cell or many cells. Most plants and animals have many cells.
The cell is the basic unit of organization in organisms.
Even in a complex organisms, the cell is the basic unit of structure and function.
All cells come from cells. Most cells can divide to form two new cells that are identical.
7.L.3A.3 Develop and use models to explain how the relevant structures within cells (including cytoplasm, cell membrane, cell wall, nucleus, mitochondria, chloroplasts, lysosomes, and vacuoles) function to support the life of plant, animal, and bacterial cells.
Cell structures / ORGANELLES● Structures that are
common to plant and animal cells are the cell membrane, nucleus, mitochondria, and vacuoles.
● Structures that are specific to plants are the cell wall and chloroplasts.
What is the function of a cell wall?● Cell Walls: a tough, rigid
outer covering that protects the cell and gives it shape
● You find cell walls in the cells of plants, algae, fungi, and most bacteria
● Cellulose is a carbohydrate that makes up a plant cell wall
What is the function of a cell wall?
● Pectin may also be found in the cell wall. It gives the cell wall strength and helps it grow and develop.
● Lignin may also be found in the cell wall. It is a compound that makes the cell wall rigid.
● Where would you find plant cells with high amounts of lignin?
Cytoplasm● The gel-like fluid inside of a cell made of mostly
water. The other organelles are embedded in the cytoplasm
● Made up of mostly water and salt
● Cytoplasm is responsible for giving a cell its shape. It helps to fill out the cell and keeps organelles in their place. Without cytoplasm, the cell would be deflated and materials would not be able to pass easily from one organelle to another.
Nucleus● Contains the genetic material
(DNA) and is the control center of the cell.
● One type of cellular reproduction, mitosis, occurs in the nucleus. This results in a duplicate copy of the cell. Mitosis is needed for growth, replacement of cells, and asexual reproduction.
Vacuole● Act as temporary storage
centers.
● Some store water; others store waste products until they can be eliminated from the cell.
● Plant cells have fewer and larger vacuoles than animal cells.
Chloroplasts
● Are the sites where photosynthesis takes place in a plant cell
● They contain the chlorophyll, the green pigment that absorbs light energy
Chloroplasts
● During the process of photosynthesis, plants use light energy (sunlight), carbon dioxide (CO2), and water (H2O) to make glucose, a simple sugar (C6H12O6) and oxygen gas (O2)
● Plant cells also release oxygen gas (O2) as a waste product of photosynthesis
Mitochondria● It is sometimes called the
“powerhouse” of the cell
● Are the energy producing sites in the cell where respiration takes place
● All organisms undergo cellular respiration. During this process, glucose (C6H12O6) is broken down into carbon dioxide (CO2) and water (H2O) to release energy
Mitochondria● The cell uses the energy to
build, repair, and reproduce cells
● Cellular respiration is the complementary process to photosynthesis
● Cells that require a larger amount of energy to function contain a larger number of mitochondria
Lysosomes● Organelles responsible for digesting certain
materials within the cell
● The lysosome can digest food, worn out organelles, as well as other cellular waste not needed for cell metabolism
Only found in animal cells
Cell membrane● The thin,
flexible outer covering of a cell. It controls what enters and leaves a cell
Two Main Ways Substances Enter and Exit a Cell:
1. Diffusion is one way in which materials (for example molecules of sugar, or waste) moves across the cell membrane. It occurs as materials move from an area of higher concentration to an area of lower concentration.
2. Osmosis is the diffusion of water across a membrane.
Concentration gradient
Concentration Gradient - change in the concentration of a substance from one area to another.
Molecules in solution tend to slowly spread apart over time. This is diffusion.
Diffusion
Diffusion● Movement of molecules from an area of high concentration
to an area of lower concentration. ●● Factors that affect the rate of diffusion: size of molecules,
size of pores in membrane, temperature, pressure, and concentration.
Diffusion
[High] [Low]
concentrated, high energy molecules
diffuse, low energy molecules
http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html
Osmosis● Osmosis is the movement of water across a
semi-permeable membrane● At first the concentration of solute is very high on the
left.● But over time, the water moves across the
semi-permeable membrane and dilutes the particles.
Osmosis – A Special kind of Diffusion● Diffusion of water across a selectively permeable
membrane (a barrier that allows some substances to pass but not others). The cell membrane is such a barrier.
● Small molecules pass through – ex: water
● Large molecules cannot pass through – ex: proteins and complex carbohydrates
http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html
PASSIVE TRANSPORT
● Passive transport occurs without expenditure of energy. Molecules move using their own kinetic energy. Diffusion and osmosis are examples of passive transport.
● Passive transport allows cells to get water, oxygen and other small molecules that they need. It also allows the cell to get rid of waste such as carbon dioxide.
DIFFUSIONOSMOSIS
7.L.3A.2 Analyze and interpret data from observations to describe different types of cells and classify cells asplant, animal, protists, or bacteria
Unicellular or Multicellular Organisms
● Unicellular organisms are composed of one cell and would include most protists and bacteria.
● Multicellular organisms are made up of lots of cells and include plants & animals
Cellular Organization
Prokaryotic or Eukaryotic● Prokaryotic cell: no membrane-bound
structures within the cell ● Lacks a nucleus● Bacteria compose the majority of prokaryotic
organisms
● Eukaryotic cell: a cell with membrane-bound structures
● Plant, animal, and protists are eukaryotic
Major structural differences between a plant and an animal cell include:
● Plant cells are usually rectangular; animal cells are usually round.
● Plant cells have a cell wall, but animal cells do not. Cell walls provide support and give shape to plants.
● Plant cells have chloroplasts, but animal cells do not. Chloroplasts enable plants to perform photosynthesis to make food.
Major structural differences between a plant and an animal cell include:
● Plant cells usually have one large vacuole, while animal cells have smaller vacuoles, if any are present. Large vacuoles help provide shape and allow the plant to store water and food for future use. The storage function plays a lesser role in animal cells, therefore the vacuoles are smaller.
Classifying an organism as photosynthetic or non-photosynthetic
● Cells that are photosynthetic contain chloroplasts and the pigment chlorophyll. This would include most cells of the plant kingdom and some protist.
● Non-photosynthesizing cells would lack chloroplasts and chlorophyll. This would include cells of the animal kingdom.
7.L.3A.4 Construct scientific arguments to support claims that bacteria are both helpful and harmful to other organisms and their environment.
Bacteria are classified by shape
Bacteria can be helpful toorganisms and the environment
● Bacteria are in our digestive system and aid in breaking down and absorbing food.
● Bacteria are used to make a variety of foods including cheese and yogurt.
● Bacteria can decompose dead organisms and release those nutrients back into the environment.
Bacteria can be harmful to organisms and the environment● Bacteria can be pathogens and cause diseases
like strep throat, food poisoning, and tuberculosis.
● Bacteria, such as wheat blight can infect plants that are used as crops.
● Other bacterial pathogens that could be considered are tetanus, bacterial pneumonia, and a variety of other infectious diseases that can affect a variety of living organisms.
Helpful & Harmful bacteria● Some bacteria can be classified as both helpful
and harmful depending on the location of infection in the human body. For example, E. coli bacteria naturally live in the human intestine. E. coli is essential for digestion to occur. However, if E. coli enters the stomach through contaminated food, it can cause foodborne illness.
7.L.3B.1 Develop and use models to explain how the structural organizations within multicellular organismsfunction to serve the needs of the organism.
The levels of organization,from the simplest level to the most complex are:
Cell - The basic units of structure and function within all living things. Though all cells perform the processes that keep the organism alive, they also have specialized functions as well.
Examples may be nerve cells (neurons), blood cells, and bone cells, in animals and guard cells, xylem cells and phloem cells in plants
The levels of organization,from the simplest level to the most complex are:
Tissue - A group of specialized cells that work together to perform a specific function.Examples of the main types of tissue in animals are nervous tissue, connective tissue, muscle tissue, and epithelial tissue. Plants contain xylem and phloem tissue that is comprised of xylem and phloem cells.
The levels of organization,from the simplest level to the most complex are:
Organs - A group of two or more different types of tissue that work together to perform a specific function. The task is generally more complex than that of the tissue.
For example, the heart is made of muscle and connective tissues which function to pump blood throughout an animal. Flowers, roots, and stems are organs in plants.
The levels of organization,from the simplest level to the most complex are:
Systems - A group of two or more organs that work together to perform a specific function. Each organ system has its own function but the systems work together and depend on one another. Plants and animals have a reproductive system.
Types of TissueNerve tissue: Carries impulses, orsignals, back and forth between thebrain and the body.
Muscle tissue: Contracts and shortens, making body parts move. There are three types of muscle tissues. Cardiac, smooth and skeletal.
Epithelial tissue: covers surfaces of the body. Inside the body, epithelial tissue serves as a lining or covering for internal organs. Forms a layer of skin outside the body.
Connective tissue: Connects all parts of the body and provides support. Examples of connective tissue includes tendons, ligaments and cartilage.
Types of Muscle TissueSmooth Muscle● Occurs in walls of
internal organs● Involuntary
Cardiac Muscle● Only occurs in the
walls of the heart● Involuntary
Skeletal Muscle● Usually attached to
bone● Voluntary
7.L.3B.2 Construct explanations for how systems in the human body (including circulatory, respiratory,digestive, excretory, nervous, and musculoskeletal systems) work together to support the essential life functionsof the body.
Nervous SystemWhat does the nervous system do for our bodies?
What organs make up the nervous system?
Nervous SystemThe main functions of the nervous system
● To receive stimuli from inside and outside the body
● To interpret the stimuli
● Initiate responses for survival
Nervous SystemThe main organs of the nervous system are:
1. Brain
2. Spinal Cord
3. Peripheral Nerves
Brain● An organ which has three distinct parts that all serve to control and coordinate the activities of the body.
● All the parts of the brain work together, but each part has its own special properties.
● The brain is divided in half into two hemispheres.
3 Main Areas of the Brain● Cerebrum - largest part of the brain
○ Controls thoughts, voluntary actions, & the sensations related to the 5 senses
● Cerebellum - small lobe located at the back of the brain○ Helps with balance and coordination
● Brain stem - located at the base of the brain○ Controls vital and involuntary processes
(breathing, heartbeat, & digestion)
Spinal CordA bundle of nerves that begins at the brainstem and continues down the center of the back through the vertebrae. It connects with the peripheral nerves.
Peripheral NervesA network of nerves that branch out from the spinal cord and connect to the rest of the body and transmit signals to and from the brain through the spinal cord.
Circulatory SystemWhat does the circulatory system do for our bodies?
What organs make up the circulatory system?
Functions of the Circulatory System
The main functions of the circulatory system is to transport blood to all parts of the body so that gases, nutrients, and waste products are transported to and from the cells.
The Main Organs
http://www.youtube.com/watch?v=nOLFVC10ctw
1) Heart - Causes blood to circulate through the body by its pumping action
2) Blood Vessels (arteries, veins, & capillaries) - tubes that carry blood throughout the entire body.
Functions of the Circulatory System● Transport gases- oxygen from the lungs to cells
around the body and carbon dioxide from the cells to the lungs.
● Transport nutrients (sugars, calcium); Transport wastes from cells to organs that are capable of breaking wastes down (liver, kidneys)
● The white blood cells within the circulatory system help to fight infection in the body.
● Maintains the pH levels and ionic concentration of fluids in the body, and Helps maintain body temperature
What are Arteries and Veins?● Most arteries carry blood that has oxygen and
nutrients to all the parts of the body.● Most veins carry waste products (for example
carbon dioxide) from all the parts of the body back to the heart.
The HeartCauses blood to circulate through the body by its pumping
action
The heart is a hollow organ about the size of a clenched fist. It is made almost entirely of muscle.
As the heart pumps blood, it creates a pressurized system that forces blood to travel through the blood vessels throughout your body, and back to the heart again, thus circulation!
Your heart pumps more than 1600 gallons a day!
The HeartThe heart has two layers:1. The outer layer of the heart is a protective film
called pericardium. (peri means outer)
2. The inner layer of the heart is known as myocardium.(myo means muscle)
The Heart has Four Chambers
The Human heart has 4 chambers, as follows: ● the right ventricle● the left ventricle● the right atrium● the left atrium.
Atria receive blood going into the heart.Ventricles pump blood out of the heart.
Blood is composed of red blood cells, white blood cells, platelets, and plasma. These components have different functions.
Functions of Blood: 1. Transportation:
a. oxygen & carbon dioxideb. nutrientsc. waste products (metabolic wastes, excessive
water, & ions)2. Regulation - hormones & heat (to regulate body
temperature) 3. Protection - clotting mechanism protects
against blood loss & leukocytes provide immunity against many disease-causing agents
What are capillaries?● Capillaries are very
small vessels where the exchange of oxygen and nutrients from the blood into the cells and carbon dioxide & other waste products enter the blood from the cells.
Respiratory SystemWhat does the respiratory system do for our bodies?
What organs make up the respiratory system?
Respiratory System
● The main function of the respiratory system is to provide gas exchange between the blood and the air.
● When air is inhaled, the lungs remove oxygen from the air. Carbon dioxide is exhaled back into the environment when it is removed from cells and carried by the blood to the lungs.
● Enables speech production.
Respiratory System● The main organs of the
respiratory system are:1) Nose-Collects air from
the environment. Moistens and heats the air before it enters the trachea.
2) Trachea-The windpipe; moves air from the nose to the lungs.
Respiratory System
3) Bronchi (e.g. bronchus)-Tubes that move air from the trachea to the lungs; one bronchus leads to each lung; part of each bronchus is outside the lung and part is inside.
Respiratory System4) Lungs-The main organs where gases are exchanged between air and the blood; the alveoli are small sacs within lung tissue. It is in the alveoli where the gas exchange takes place.
Respiratory System5) Diaphragm - The muscle that aids in the breathing process and allows the rib cage to expand
Digestive SystemWhat does the digestive system do for our bodies?
What organs make up the digestive system?
Digestive SystemThe main functions of the digestive system are:
● To break down foods into nutrients that can be used by the body
● Absorb nutrients that are necessary for energy, growth, and maintenance
● Rid the body of solid wastes
Digestive System
● The organs of the digestive system can be divided into two categories, primary and secondary.
● Primary organs have a direct role in digesting food and come into physical contact with the food
● Secondary organs support the process of digestion by secreting digestive juices. Food does not pass through secondary organs
Primary Organs● Mouth
● Begins to break down food into smaller pieces through mechanical digestion; saliva in the mouth starts the process of chemical digestion
● Esophagus● Tube that carries chewed food to the stomach
● Stomach● Continues the process of mechanical
digestion; secretes gastric juices that continue the process of chemical digestion started in the mouth
Primary Organs● Small Intestines
● The organ where most of the chemical digestion of food takes place; nutrients from food are also absorbed into the bloodstream through the small intestines
● Large Intestines● The organ where water from the
food is absorbed into the bloodstream; prepares the remaining undigested food for elimination from the body
Primary Organs● Rectum
● A short tube that stores solid waste until it is eliminated from the body
● Anus● Opening where solid waste is eliminated
Secondary Organs● Liver
● Produces bile, which is used by the body to break up fat, and filters blood
● Gallbladder● Stores bile produced by the liver
● Pancreas● Produces digestive juices that
help to further break down the food in the small intestine
Excretory SystemWhat does the excretory system do for our bodies?
What organs make up the excretory system?
Excretory (Urinary) SystemThe main function of the excretory system:Eliminate wasteFilter cellular wastes, toxins, excess water that result from cellular respiration
Excretory (Urinary) System
● The main function of the excretory system is to filter cellular wastes, toxins (chemicals that could be poisonous to the body), and excess water that result from cellular respiration.
● The main organs of the excretory (urinary) system are:
1) Kidneys-The two kidneys get rid of urea, excess water, and some other waste materials released by the cells. These are eliminated as urine.
2) Ureters-Tubes which connect each kidney to the bladder.
3) Bladder-A saclike muscular organ which stores urine until it is released from the body.
4) Urethra-Tube through which urine passes before it is removed from the body
Musculoskeletal SystemThe main functions of the musculoskeletal system:● Provide movement and
support for the body● Protect internal organs● Provide attachment
sites for the muscles
Musculoskeletal SystemThe main organs of the musculoskeletal system are:● Muscles
● Soft tissue that has the ability to relax and contract in order to initiate movement within the body
Musculoskeletal SystemThere are three types of muscle:● Cardiac muscles
● Involuntary muscle that forms the heart
● Smooth muscles ● Involuntary muscles that control many
types of movement within the body (such as digestion).
● Skeletal muscles ● Voluntary muscles attached to bones
and provide the force needed to move the bones; tendons connect the skeletal muscles to bones
Musculoskeletal SystemBones
● Provide shape and support for the body
● Protection for many organs and structures
● Attachment sites for muscles
● Some bones produce blood cells
● Store minerals
Musculoskeletal System● Joints
● A place in the skeleton where two or more bones meet
● There are many types of joints found in the body
Musculoskeletal System● Ligaments
● Soft connective tissue that attach bones at the joints● Tendons
● Soft connective tissue that attaches muscles to bones
Relationships of the Major Body SystemsEven though each system in the human body performs its own function, the different systems work together and depend on one another for the body to function successfully.
● Examples of relationships between the major body systems may be:● All body systems are dependent upon the
circulatory system to transport materials.
Relationships of the Major Body Systems
● The circulatory system works with the excretory system to help remove wastes from the body.
● The respiratory system works with the circulatory system to make sure that oxygen (O2) reaches the bloodstream and carbon dioxide (CO2) is removed from the bloodstream.
● The digestive system works with the circulatory system to make sure that nutrients made available by digestion (for example glucose) get to the cells of the body.
Relationships of the Major Body Systems
● The nervous system works with the muscular and skeletal systems to direct behavior and movement.
● The nervous system controls internal processes in the body (for example digestion and circulation).
● Muscles control the movement of materials through some organs (for example the stomach, intestines, and the heart).