all life is cellular! (the rest is just details.)
TRANSCRIPT
ALL LIFE IS ALL LIFE IS CELLULAR!CELLULAR!
(The rest is just details.)(The rest is just details.)
ImagesImages
Types Types
OrganellesOrganelles
QuizQuiz
A View ofA View of the Cellthe Cell
History & History & MicroscopesMicroscopes
MembraneMembrane
What do What do they do?they do?
What What about about cells?cells?
Cell Cell ImagesImages
#1#1
BacteriaBacteria
LeafLeaf
CellsCells
#2#2
StriatedStriatedMuscleMuscle
BloodBloodCellsCells #3#3
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imagesCytoplasmic
streaming
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What am What am I seeing?I seeing?
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images
Towhat am I seeing?
CH
RO
MO
SO
ME
SO
f DN
A!
NUCLEUS
What am I seeing?What am I seeing?
These are onion cells. These are onion cells. The “boxes” are the actual cellsThe “boxes” are the actual cells What is the dark round structure inside What is the dark round structure inside
the cells?the cells? What are the “stringy” structures in some What are the “stringy” structures in some
cells?cells? Go Back and click on these to find out.Go Back and click on these to find out.
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What Is
This?
Various blood cellsVarious blood cells
What kind of blood cell is What kind of blood cell is this?this?
It is a Red Blood CellIt is a Red Blood CellAlso, known as an Also, known as an
ErythrocyteErythrocyteTheir function is to Their function is to transport oxygen transport oxygen
throughout the blood.throughout the blood.
What kind of blood cell is What kind of blood cell is this?this?
It is a type of White Blood It is a type of White Blood Cell.Cell.White blood cells are known White blood cells are known as Leukocytes.as Leukocytes.There are many kinds of There are many kinds of WBC’s. They work within the WBC’s. They work within the immune system to fight immune system to fight invaders. What are some invaders. What are some types of invaders?types of invaders?
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images
How Big Is it?
Actually, this is not big at all. It is Actually, this is not big at all. It is a bacterial cell and is about a bacterial cell and is about 1/10,0001/10,000thth the size of the other the size of the other cells you have viewed.cells you have viewed.
Are bacteria cells the same as all other Are bacteria cells the same as all other types of cells?types of cells?
How are bacterial cells classified?How are bacterial cells classified?
Are all bacteria harmful?Are all bacteria harmful?
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Characteristics of Characteristics of Bacteria CellsBacteria Cells
They are Prokaryotic Cells not Eukaryotic CellsThey are Prokaryotic Cells not Eukaryotic Cells This means they do not have membrane This means they do not have membrane
covered nuclei or organelles inside. The DNA covered nuclei or organelles inside. The DNA is in a “region” of the cell, but they do have is in a “region” of the cell, but they do have ribosomes which don’t have a membrane.ribosomes which don’t have a membrane.
They have a cell wall but not made of cellulose They have a cell wall but not made of cellulose like plant cell walls. It is made of peptidoglycan like plant cell walls. It is made of peptidoglycan – a combination of protein and carbohydrates.– a combination of protein and carbohydrates.
All bacteria belong to Kingdom Monera and all All bacteria belong to Kingdom Monera and all Monerans are prokaryotes and all prokaryotes Monerans are prokaryotes and all prokaryotes are Monerans.are Monerans.
Classifying BacteriaClassifying Bacteria ShapeShape
SphericalSpherical - Cocci / Coccus- Cocci / Coccus Example: Example: Streptococcus pyrogenesStreptococcus pyrogenes
Rod likeRod like - Bacilli / Bacillus- Bacilli / Bacillus Example: Example: Bacillus anthracis
SpiralSpiral - Spiralli / Spirallis- Spiralli / Spirallis Example: Example: Vibrio cholerae
Gram Staining Test Technique Test Technique
Light microscope image
Yuk! Strep throat!
What is this?What is this? The 3 types of muscle cells:The 3 types of muscle cells:
SkeletalSkeletal cardiaccardiac smooth smooth Can you see the striped appearance of these cells?Can you see the striped appearance of these cells?
““Striated” means striped – this is striated skeletal Striated” means striped – this is striated skeletal muscle muscle
The stripes are a result of light and dark bands The stripes are a result of light and dark bands within within individual muscle cells called “individual muscle cells called “sarcomeres” sarcomeres”
The striated muscle fibers are made up of actin and The striated muscle fibers are made up of actin and myosin (proteins that can contract/shorten) which meet myosin (proteins that can contract/shorten) which meet like zipper teeth. A muscle contracts (shortens) when like zipper teeth. A muscle contracts (shortens) when the myosin and actin elements are pulled together the myosin and actin elements are pulled together along their length. along their length.
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Electron microscope image
Light microscope imagew/ Gram stain
•Determines the type of cell wall a bacteria has•Slides are washed successively in the following
dyes: crystal violet, iodine, alcohol, safranin•Gram positive organisms are purple (or bluish)•Gram negative organisms are red•Helpful in determining treatment for bacterial infections – which medicine should you take?
Gram Negative Gram Positive
Two major types of cellsTwo major types of cells ProkaryotesProkaryotes
Cells without true nucleus; Cells without true nucleus; not surrounded by a not surrounded by a membranemembrane
Has DNA in a nucleoid Has DNA in a nucleoid regionregion
No membrane-bound No membrane-bound organellesorganelles
Has ribosomesHas ribosomes Has a cell wall – not made Has a cell wall – not made
of cellulose like plant cell of cellulose like plant cell walls; Made of walls; Made of peptidoglycan – peptidoglycan – a a combination of protein combination of protein and carbohydrateand carbohydrate
Only bacteria are Only bacteria are prokaryotic cellsprokaryotic cells
EukaryotesEukaryotes Cells with a true Cells with a true
nucleus(DNA) surrounded nucleus(DNA) surrounded by a membraneby a membrane
DNA in a nucleusDNA in a nucleus Organelles covered in a Organelles covered in a
membranemembrane PlantsPlants AnimalsAnimals FungiFungi One celled ProtistsOne celled Protists
AmoebaAmoeba AlgaeAlgae EuglenaEuglena parameciumparamecium
PROKARYOTES
EUKARYOTES
Plant and Animal Cells
Cells that do not contain internal membrane-bound structures are called prokaryotic cells.
• The cells of unicellular bacteria do not have membrane bound structures and are therefore called prokaryotes.
Two Basic Cell TypesTwo Basic Cell Types
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PROKARYOTIC CELLSPROKARYOTIC CELLS
EUKARYOTIC CELLSEUKARYOTIC CELLS
PLANT CELLSPLANT CELLS
ANIMAL CELLSANIMAL CELLS
The Life of a Cell
A View of the Cell
A cell is the basic unit of life.
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The History of the Cell TheoryThe History of the Cell Theory• Before microscopes were invented, people
believed that diseases were caused by curses and supernatural spirits.
• Microscopes enabled scientists to view and study cells, the basic units of living organisms.
• As scientists began using microscopes, they quickly realized they were entering a new world–one of microorganisms.
The first person to record looking at water The first person to record looking at water under a microscope was Anton vanunder a microscope was Anton van LeeuwenhoekLeeuwenhoek..
The microscope van Leeuwenhoek used is The microscope van Leeuwenhoek used is considered a simple light microscope because considered a simple light microscope because it contained one lens and used natural light to it contained one lens and used natural light to view objects.view objects.
Development of Light MicroscopesDevelopment of Light Microscopes
Compound light microscopes use a series of lenses to magnify objects in steps.
These microscopes can magnify objects up to 1 500 times.
Development of Light MicroscopesDevelopment of Light Microscopes
• Robert Hooke was an English scientist who lived at the same time as van Leeuwenhock.
The Cell TheoryThe Cell Theory
• Hooke used a compound light microscope to study cork, the dead cells of oak bark.
Cells are the basic building blocks of all living things.
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The The cell theorycell theory is made up is made up of three main ideas:of three main ideas:
All cells come from preexisting cells.
The cell is the basic unit of organization of organisms.
All organisms are composed of one or more cells.
Electron microscopesBack to menu
The electron microscope was invented in the 1940s.The electron microscope was invented in the 1940s.
This microscope This microscope uses a beam of uses a beam of electrons to electrons to magnify magnify structures up to structures up to 500 000 times 500 000 times their actual size. their actual size.
Development of Electron MicroscopesDevelopment of Electron Microscopes
There are two basic types of electron microscopes.There are two basic types of electron microscopes.
The transmission electron microscope allows scientists to study the structures contained within a cell.
The scanning electron microscope scans the surface of cells to learn their three dimensional shape.
Development of Electron MicroscopesDevelopment of Electron Microscopes
A prokaryotic cell does not have internal organelles surrounded by a membrane. Most of a prokaryote’s metabolism takes place in the cytoplasm.
• Ribosomes
(the dots)
2. DNA 3. Plasma membrane
4. Cell wall
5. Flagellum6. Cytoplasm
This eukaryotic cell from an animal has distinct membrane-bound organelles that allow different parts of the cell to perform different functions.
4. Plasma membrane
1. Nucleus
2. Nucleolus
3. DNA/Chromosomes
5. Other Organelles
The membrane-bound structures within The membrane-bound structures within eukaryotic cells are called eukaryotic cells are called organellesorganelles..
Each organelle has a specific function that Each organelle has a specific function that contributes to cell survival.contributes to cell survival.
• Separation of organelles into distinct compartments benefits the eukaryotic cells.
The nucleus is the central membrane-bound organelle that manages cellular functions.
The Plasma MembraneThe Plasma Membrane
PLANT CELLS
ANIMAL CELLS
The plasma The plasma membrane acts as membrane acts as a selectively a selectively permeable permeable membrane.membrane.
Cellular BoundariesCellular Boundaries
The cell wallThe cell wall The cell wall is a fairly rigid structure located outside the plasma membrane that provides additional support and protection.
Nucleus and cell controlNucleus and cell control
Chromatin
Nucleolus
Nuclear Envelope
Assembly, Transport, and Assembly, Transport, and StorageStorage
TheThe endoplasmic endoplasmic reticulum (ER)reticulum (ER) is is an organelle that an organelle that is suspended in is suspended in the cytoplasm the cytoplasm and is the site of and is the site of cellular chemical cellular chemical reactions.reactions.
Assembly, Transport, and Assembly, Transport, and StorageStorage
Endoplasmic Reticulum (ER)
Ribosomes
Assembly, Transport, and Assembly, Transport, and StorageStorage
Golgi Apparatus
Vacuoles and storageVacuoles and storage Vacuoles are membrane-bound spaces used for temporary storage of materials. Notice the difference between vacuoles in plant and animal cells.
VacuoleAnimalCell
PlantCell
Lysosomes and recyclingLysosomes and recycling Lysosomes are organelles that contain digestive enzymes. They digest excess or worn out organelles, food particles, and engulfed viruses or bacteria.
Energy Transformers:Energy Transformers:
Chloroplasts are cell organelles that capture light energy and produce food to store for a later time.
Chloroplasts and energyChloroplasts and energy
The chloroplasts belongs to a group of plant organelles called plastids, which are used for storage.
Chloroplasts contain green pigment called chlorophyll. Chlorophyll traps light energy and gives leaves and stems their green color.
Chloroplasts and energyChloroplasts and energy
Mitochondria are membrane-bound organelles in plant and animal cells that transform energy for the cell.
Mitochondria and energyMitochondria and energy
A mitochondria, like the endoplasmic reticulum, has a highly folded inner membrane. Energy storing molecules are produced on inner folds.
Mitochondria and energyMitochondria and energy
Cells have a support structure called the cytoskeleton within the cytoplasm. The cytoskeleton is composed of microtubules and microfilaments. Microtubules are thin, hollow cylinders made of protein and microfilaments are thin solid protein fibers.
Structures for Support and Structures for Support and LocomotionLocomotion
Some cell surfaces have cilia and flagella, which are structures that aid in locomotion or feeding. Cilia and flagella can be distinguished by their structure and by the nature of their action.
Cilia and flagellaCilia and flagella
Cilia are short, numerous, hair-like projections that move in a wavelike motion.
Cilia and Cilia and flagellaflagella Cilia
Flagella are long projections that move in a whip-like motion. Flagella and cilia are the major means of locomotion in unicellular organisms.
Cilia and Cilia and flagellaflagella
Flagella
All living cells must maintain a balance regardless of internal and external conditions. Survival depends on the cell’s ability to maintain the proper conditions within itself.
Why cells must control Why cells must control materialsmaterials
The The plasma plasma membranemembrane is the is the boundary between boundary between the cell and its the cell and its environment. environment.
It is the plasma membrane’s job to:It is the plasma membrane’s job to:
• allow waste and other products to leave the cell.
• remove excess amounts of these nutrients when levels get so high that they are harmful.
• allow a steady supply of glucose, amino acids, and lipids to come into the cell no matter what the external conditions are.
Selective permeabilitySelective permeability is a process used to is a process used to maintain homeostasis in which the plasma maintain homeostasis in which the plasma membrane allows some molecules into the membrane allows some molecules into the cell while keeping others out.cell while keeping others out.
This process of maintaining the cell’s This process of maintaining the cell’s environment is called environment is called homeostasishomeostasis..
Water
Plasma Membrane
Structure of the Plasma Structure of the Plasma MembraneMembrane
The plasma The plasma membrane is membrane is composed of two composed of two layers of layers of phospholipids phospholipids back-to-back.back-to-back.
Phospholipids are lipids with a phosphate attached to them.
The lipids in a The lipids in a plasma membrane plasma membrane have a glycerol have a glycerol backbone, two backbone, two fatty acid chains, fatty acid chains, and a phosphate and a phosphate group.group.
Glycerol Backbone
Two Fatty Acid Chains
Phosphate Group
Makeup of the phospholipid Makeup of the phospholipid bilayerbilayer
The phosphate The phosphate group is critical for group is critical for the formation and the formation and function of the function of the plasma plasma membrane.membrane.
Phosphate Group
Makeup of the phospholipid Makeup of the phospholipid bilayerbilayer The The fluid mosaic fluid mosaic
modelmodel describes describes the plasma the plasma membrane as a membrane as a flexible boundary flexible boundary of a cell. The of a cell. The phospholipids phospholipids move within the move within the membrane.membrane.
The Plasma MembraneThe Plasma Membrane
Other components of the Other components of the plasma membrane:plasma membrane:
Cholesterol plays the important role of Cholesterol plays the important role of preventing the fatty acid chains of the preventing the fatty acid chains of the phospholipids from sticking together.phospholipids from sticking together.
CholesterolMolecule
Other components of the Other components of the plasma membrane:plasma membrane:
Transport proteinsTransport proteins allow needed allow needed substances or waste materials to move substances or waste materials to move through the plasma membrane.through the plasma membrane.
What happens in cells?What happens in cells? Control of cell functionsControl of cell functions Photosynthesis Photosynthesis Protein, lipid, carb. productionProtein, lipid, carb. production DigestionDigestion ContractionContraction SecretionSecretion Energy transformationsEnergy transformations ProtectionProtection SupportSupport Information transferInformation transfer Detect informationDetect information othersothers
There are many kinds of There are many kinds of cells cells
All are specialized to do All are specialized to do different thingsdifferent things
Not all cells perform all Not all cells perform all functionsfunctions
Cells are very Cells are very specializedspecialized
1.How did the invention of the microscope 1.How did the invention of the microscope impact societyimpact society’’s understanding of disease?s understanding of disease?
B. Microscopes were invented after the development of the cell theory.
A. Scientists were able to view microorganisms that were previously unknown.
D. Scientists could view membrane-bound organelles of prokaryotes.
C. It was once believed that viruses, not bacteria, caused diseases.
The answer is AThe answer is A. . Before microscopes were Before microscopes were invented, people believed that curses and invented, people believed that curses and supernatural spirits caused diseases. supernatural spirits caused diseases. Microscopes enabled scientists to view cells, Microscopes enabled scientists to view cells, which led to the discovery that microorganisms which led to the discovery that microorganisms cause some diseases.cause some diseases.
2. Which of the following uses a beam of light 2. Which of the following uses a beam of light and a series of lenses to magnify objects in and a series of lenses to magnify objects in steps?steps?
D. simple light microscope
C. transmission electron microscope
B. scanning electron microscope
A. compound light microscope
The answer is AThe answer is A. Most microscopes use at least . Most microscopes use at least two convex lenses. Compound light microscopes two convex lenses. Compound light microscopes use a light beam and a series of lenses and can use a light beam and a series of lenses and can magnify objects up to about 1500 times. Electron magnify objects up to about 1500 times. Electron microscopes use a beam of electrons and can microscopes use a beam of electrons and can magnify structures up to 500 000 times.magnify structures up to 500 000 times.
Plasma membrane
Nucleus
Nucleolus
Chromosomes
Organelles
3. 3. What makes this cell eukaryotic?What makes this cell eukaryotic?
A. Because it has a cell wall.
B. Because it contains DNA.
C. Because it has membrane-bound organelles.
D. Because it does not have DNA.
Plasma membrane
Nucleus
Nucleolus
Chromosomes
Organelles
The Answer is C.The Answer is C. Eukaryotic cells contain Eukaryotic cells contain membrane-bound organelles that have specific membrane-bound organelles that have specific functions in the cell; prokaryotic cells do not.functions in the cell; prokaryotic cells do not.
4. 4. Describe the Describe the structure of the structure of the plasma membrane.plasma membrane.
The plasma membrane is composed of a The plasma membrane is composed of a phospholipid bilayer, which has two layers of phospholipid bilayer, which has two layers of phospholipids back-to-back. The polar heads of phospholipids back-to-back. The polar heads of phospholipid molecules contain phosphate phospholipid molecules contain phosphate groups and face outward. groups and face outward.
5. Why is the 5. Why is the phosphate phosphate group of a group of a phospholipid phospholipid important to the important to the plasma plasma membrane?membrane?
Polar head (includes phosphate group)
Nonpolar tails (fatty acids)
Phospholipid molecule
When phospholipid molecules form a bilayer, the phosphate groups lie to the outside. Because phosphate groups are polar, they allow the cell membrane to interact with its watery (polar) environments inside and outside the cell.
Polar head (includes phosphate group)
Nonpolar tails (fatty acids)
Phospholipid molecule
6. 6. Explain why the model of the plasma Explain why the model of the plasma membrane is called the fluid mosaic model.membrane is called the fluid mosaic model.
It is fluid because the phospholipid molecules move within the membrane. Proteins in the membrane that move among the phospholipids create the mosaic pattern.
7. What is the primary function of the cell wall?7. What is the primary function of the cell wall?
D. acquire nutrients from environment
C. control activity of organelles
B. provide support
A. act as selectively permeable membrane
The answer is B. The cell wall is an inflexible, porous barrier that provides support but does not select which molecules can enter the cell.
DNA
Plasma membrane
Cell wall
8. Describe the control center of a prokaryotic cell.
Ribosomes
DNA
Plasma membrane
Cell wall
Prokaryotic cells do not have true nuclei; their DNA is not separated from the rest of the cell by a membrane.
Ribosomes
9. 9. Which of the following structures is the site of Which of the following structures is the site of protein synthesis?protein synthesis?
D. Lysosome
C. Vacuole
B. Ribosome
A. Golgi apparatus
The answer is B. Ribosomes are the sites where the cell produces proteins according to the directions of DNA. They can be attached to the surface of the endoplasmic reticulum or float freely in the cytoplasm.
10. 10. What is the advantage of having numerous What is the advantage of having numerous folds in the ER?folds in the ER?
B. It can create more vesicles in a smaller space.
A. It enables the ER to lie snugly against the nucleolus.
D. A large amount of work can be done in a small space.
C. It can capture more light energy with more folds.
The answer is D. The ER is arranged in a series of folded membranes, which, if spread out, would take up tremendous space.
B. It contains a greater number of plastids.
11. 11. What could you predict about a plant cell that What could you predict about a plant cell that contains fewer chloroplasts than other plant cells?contains fewer chloroplasts than other plant cells?
A. It contains less chlorophyll.
D. It will appear darker green in color.
C. It will have an increased rate of light energy capture.
The answer is A. Chloroplasts are among the plant organelles known as plastids and contain the green pigment chlorophyll. Chlorophyll traps light energy from the Sun and gives leaves and stems their green color.
12. 12. A mutation results in the inner membranes of A mutation results in the inner membranes of a liver cell’s mitochondria being a liver cell’s mitochondria being smooth, rather smooth, rather than folded. Which of the following would you than folded. Which of the following would you expect? expect?
B. it can create more vesicles in a smaller space
A. more efficient storage of cellular energy
D. fewer ribosomes available for protein synthesis
C. decreased energy available to the cell
The answer is C. Mitochondria transform energy for the cell. A highly folded inner membrane provides a greater surface area for producing energy-storing molecules.
12. Which of the following is a main idea of the cell theory?
D. All cells come from preexisting cells.
C. All cells come from two parent cells.
B. The organelle is the basic unit structure and organization of organisms.
A. All organisms are composed of one cell.
The answer is D. The cell theory states that a cell divides to form two identical cells.
13. In what type of cell would you find chlorophyll?
D. fungus
C. plant
B. animal
A. prokaryote
The answer is C. Chlorophyll is the green pigment found in the chloroplasts of plant cells.
14. Which of these structures packs proteins into membrane-bound structures?
A. B.
C. D.
Answer C depicts the Golgi apparatus, which sorts proteins and packs them into vesicles.
15. What is the difference between the cell wall and the plasma membrane?
Cell wall
Plasma membrane
Inside cell
Outside cell
The plasma membrane is a flexible boundary between the cell and its environment that controls the supply of nutrients, waste, and other products entering and leaving the cell. The cell wall is a rigid structure found in plant cells, fungi, bacteria and some protists that provides support and protection but does not select which molecules can enter or leave the cell.
Cell wall
Plasma membrane
Inside cell
Outside cell
16. Which of the following organelles is not bound by a membrane?
D. lysosome
C. vacuole
B. Golgi apparatus
A. ribosome
The answer is A. Ribosomes are simple structures made of RNA and protein and are not bound by membranes.
Ribosomes
17. Explain the importance of cholesterol to the plasma membrane.
Cholesterol molecule
Phospholipid molecules
Cholesterol helps to stabilize the phospholipids in the plasma membrane by preventing their fatty acid tails from sticking together.
Cholesterol molecule
Phospholipid molecules
18. In which of the following pairs are the terms related?
D. plastid – storage
C. microfilaments – locomotion
B. prokaryote – mitochondria
A. cell wall – selective permeability
The answer is D. Plastids are plant organelles that are used for storage.
19.Which of the following structures is found in both plant and animal cells?
D. thylakoid membrane
C. mitochondrion
B. cell wall
A. chloroplast
The answer is C. Mitochondria are the organelles in both plant and animal cells that transform energy for the cell.
20. __________ span the entire plasma membrane and regulate which molecules enter and leave the cell.
D. Microtubules
C. Ribosomes
B. Cholesterol molecules
A. Transport proteins
The answer is A. Transport proteins form the selectively permeable membrane and move needed substances or waste materials through the plasma membrane.
21. Compare the cytoskeleton of a cell to the skeleton of the human body.
The cytoskeleton and skeleton are similar in that both form a framework. However, the cytoskeleton is a constantly changing structure with the ability to be disassembled in one place and reassembled in another.
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The History of the Cell TheoryThe History of the Cell Theory
•Rene Dutrochet- Cell is the basic functional unit of life
Anton van Leeuwenhoek - first person to record observing with a microscope; 1600’s
Looked at water organisms•Robert Hooke- 1600’s; used a microscope to study cork;
termed the word “cell”; •Matthias Schleiden -1830’s; All plants made of cells•Theodor Schwann – 1830’s; All animals made of cells
•Rudolph Virchow – all cells come from preexisting cells