Post on 26-Dec-2015
Cells and OrganellesChapter 4 – Cells: The Basic Units of
LifeM.Elizabeth
Martin Luther King, Jr. JHS2005
Chapter 4 Cells: The Basic Units of Life
4.1 Organization of Life 4.2 The Discovery of Cells 4.3 Eukaryotic Cells: The Inside
Story Review
4.1 Organization of Life
Cells: Starting Out SmallTissues: Cells Working in TeamsOrgans: Teams Working TogetherOrgan Systems: A Great CombinationOrganisms: Independent LivingThe Big Picture –
PopulationsCommunitiesEcosystemsBiosphere
4.2 The Discovery of CellsSeeing the First CellsSeeing Cells in Other Life FormsThe Cell TheoryCell Similarities
Cell MembraneHereditary MaterialCytoplasm and OrganellesSmall Size
Giant Amoeba Eats New York City – Surface to Volume Ratio limitations
The Benefits of Being MulticellularTwo Types of Cells
ProkaryotesEukaryotic Cells
4.3 Eukaryotic Cells: The Story Inside
Holding It All Together Cell Membrane Cell Wall
The Cell’s Library - nucleusProtein Factories – ribosomesThe Cell’s Delivery SystemThe Cell’s Power Plants
MitochondriaChloroplastsEndosymbiotic Theory
The Cell’s Packaging CenterThe Cell’s Storage CentersPackages of DestructionPlant or Animal
4.1 Organization of Life Cells: Starting Out Small Terms
Tissue – a group of similar cells that work together to perform a specific job (function) in the body
Organ – A combination of two or more tissues that work together to perform a specific function in the body
Organ System – Groups of organs working together to perfomr body functions
Organism – anything that can live on its own
Unicellular – made of one cell Multicellular – made of many cells
4.1 Organization of Life Cells: Starting Out Small Terms (continued)
Population – a group of individuals of the same species that live together in the same area at the same time
Community – All of the populations of different species that live and interact in an area
Ecosystem – a community of organisms and their non-living (abiotic) environment
Biosphere – all life on Earth
Cells Starting Out Small Example of a cell that is
large enough to be seen without a microscope: Chicken egg – The first cell
of a chick is yellow with a tiny white dot in it and it is surround by a clear jellylike fluid called egg white The white dot divides over and over again to form a chick. The yellow yoke from the first cell and the egg white provide the nutrients for the developing chick’s cell growth.
Humans have about 200 different kinds of cells and each type is specialized to do a particular job.Tissues: Cells Working TogetherTissues are groups of cells that work together to perform a specific functionOrgans: Tissues working togetherTwo or more tissues working together
The skin is the body’s largest organ. An average person’s skin has a mass of about 4.5 kg (almost 10 lbs)
In your lifetime you will shed about how much dead skin?
18 kg (almost 40 lbs)
Plant Organs
1. Leaf2. Flower3. Fruit4. Stem5. Seed6. Root
http://www.urbanext.uiuc.edu/gpe/case1/c1m1app.html
Organ Systems: A Great Combination
Organs working together in groups to perform particular functions are called organ systems.
Organ system card activity
From Cell to Organ System
Muscle cell makes up heart tissue that makes up a heart (organ) that is part of the circulatory/cardiovascular system.
Respiratory System
Inhalation (Breathing in) Exhalation (Breathing out)
Humans in and out Fish in the mouth the mouth with water through the gills and out
Skeletal System
Skeletal System – Bone Tissue
Bone has calcium salts in the matrix, giving it greater strength. Bone also serves as a reservoir (or sink) for calcium.
Protein fibers provide elasticity while minerals provide strength. Two types of bone occur.
Dense bone has osteocytes (bone cells) located in lacunae connected by canaliculi. Lacunae are commonly referred to as Haversian canals.
Spongy bone occurs at the ends of bones and has bony bars and plates separated by irregular spaces. The solid portions of spongy bone pick up stress..
Note the haversian canal and surrounded by osteocytes and a mineralized matrix
Organisms: Independent Living
Anything that can live on its own is an organism. Recall virus are not considered living –
here is another reason way – because they cannot live on their own.
Unicellular organisms– one cell, usually requires a microscope to view.
Multicellular organisms A group of cells that can remain alive
only together as a unit.
Plant Organ Systems
In flowering plants, the flower functions in sexual reproduction.
The essential flower parts are: male parts called the stamens female part called the pistil.
The stamen is the male plant organ and has two parts: anthers and
filaments.
Pollen (usually yellow) is produced at the ends of the stamens on structures called anthers.
Anthers are supported by a thread-like structure called a filament.
The pistil which is the female plant organ has three parts: stigma, style, and
ovary.
The stigma is the sticky surface at the top of the pistil; it traps and holds the pollen.
The style is the tube-like structure that supports the stigma.
The style leads down to the ovary which contains the ovules.
During the process of pollination
1. Pollen moves from the male parts to the female parts.
2. Pollen grains land on the stigma 3. A tiny tube grows from it and down the style into
the ovary.4. Sperm cells travel down the tube from the pollen
grains and join with an egg cell in the ovule resulting in fertilization.
5. The fertilized ovule becomes the seed and the ovary becomes the fruit.
The Big Picture Organisms interact in populations:
All of the red oak trees make up the forest’s red oak population.
Communities include two or more different populations living in the same area. The populations of foxes, oak trees,
lizards, flowers, and other organisms in a forest are all part of a particular forest community
Ecosystems: Community and all nonliving things (abiotic) like: water, soil, rocks, temperature, and light.
Sample Ecosystem
What makes up a community?A community is made up of the populations of
living things (biotic) in the ecosystem. So the community in the ecosystem is the deer, butterflies, trees, grasses, and flowers.
4.2 The Discovery of CellsSeeing the First Cells Robert Hooke: 1665 British
scientist. Looking for demonstration for a scientific meeting. Hooke looked at a piece of cork and noticed hundreds of little boxes. He named the little
boxes cells which means in Latin “little rooms”
http://www.roberthooke.org.uk/
Seeing Cells in Other Life Forms
Anton Leeuwenhoek Used his own handmade microscope that be built to look more closely at fabrics he was buying while in Holland.
Looked at blood, teeth tarter and all kinds of living cells. He also discovered that yeasts that make bread are unicellular.
The Cell Theory1. All organisms are composed of one or
more cells2. The cell is the basic unit of life in all living
things3. All cells come from existing cells
Three scientists involved:1. Matthias Schleiden (1838) German, plant cells2. Theordor Schwann (1839) German, animal
cells. Wrote the first two tenets of the theory.3. Rudolf Virchow (1858) German doctor. Wrote
the last tenet after observing that cells could not develop from anything but other cells.
Cell Similarities All Cells have the following in common:
Cell membranes – barriers to the outside world. Control the passage of materials into and out of the cell.
Hereditary Material – DNA (deoxyribonucleic acid) or sometimes RNA (ribonucleic acid)
Cytoplasm and Organelles Cytoplasm is the fluid that is contained within
the cell and that the organelles are found. Not all cells have membrane-bound organelles (nucleus, mitochondria, chloroplasts, golgi, etc.)
Small size – too small to be seen by the eye.
Giant Amoeba Eats New York City
The surface area and volume of a cube can be found with the following equations: SA = 6L2 , and V = L3
where S = surface area (in units squared), V = volume (in units cubed), and
L= the length of one side of the cube.
What is important about Surface-to-Volume
Cells need food, energy, and to remove wastes and heat in proportion to its size or volume, V
All of these things must be transported across the cell's surface, S, so the rate at which needs can be met is proportional to the surface area.
Size small structures that are more "surfacey" than large structures can meet their needs faster.
This can be seen by considering 2 cubes of different size.
Surface Area = S = 6r2
Volume = V = r3
Surface/Volume = S/V = 6/r
Surface to Volume Ratio
It is harder for nutrients and wastes to get in and out from the central area of larger cells
Cell Surface Area to Volume
What are the two types of cells?
Eukaryotic cellsEukaryotic cells – have a nucleus and other membrane bound organelles
Prokaryotic cellsProkaryotic cells – do not have a nucleus or other membrane bound organelles
Prokaryotes
no nucleusno membranes except cell membrane
bacteria or blue/green algaevery smallalmost always unicellularribosomessingle circular DNA chromosome
Eukaryotesnucleus (eukaryotic means “true nucleus” in Greek)
membrane bound Organelles larger in sizeuni or multicellularmany linear DNA chromosome evidence indicates that they first appeared about 2 billion years ago during the Precambrian Era.
animals, plants, fungi, protista
4.3 Eukaryotic Cells: The Inside Story
Holding it all togetherCell Membrane - phospholipidsCell Wall
Plant cells – cellulose cell wallFungal cells – chitan usually
Cell Membrane The cell membrane is a structure that
forms the outer boundary of the cell and allows only certain materials to move into and out of the cell.
Food, oxygen and water move into the cell through the membrane. Waste products also leave through the membrane.
Cells that perform photosynthesis (plants and some protists) take in carbon dioxide through the cell membrane instead of oxygen.
Cell Membrane Function
The cell membrane allows only certain materials to move in and out of the cell
Looks like this Functions like this
Cell Membrane Composition The current best model of what a cell
membrane looks like is in the figure below. As you can see it is made up of three parts. phospholipids (magenta and green) proteins (orange and red) carbohydrates (black). Carbohydrates can be
attached to either the phospholipids or the proteins in the cell membrane.
The Cell’s Library - Nucleus
Nucleus – means “kernel or nut” because it is the “essence of cells”
In all except for plant cells is the largest and most visible organelle.
Is called the control center of the cell Stores DNA which has the information to
make all of the cell’s proteins. The dark central area is called the
nucleolus which stores materials to make ribosomes in the cytoplasm (RNA)
Protein Factories - Ribosomes
Proteins are the building blocks of all cells
Proteins are made up amino acids Ribosomes make proteins by linking
amino acids together in accordance with the information stored in DNA
All cells have ribosomes because all cells need proteins to live
Ribosomes are not covered with a membrane – NOT Membrane Bound
Review
Do prokaryotic cells have ribosomes?
Yes, prokaryotes have ribosomes because ribosomes are essential and are not membrane bound.
Cell’s Delivery System – Endoplasmic Reticulum
Membrane covered Flattened sacks stacked side by side May be covered with ribosome
(rough endoplasmic reticulum) Makes lipids and other materials for
use inside and outside of the cell. Is an internal delivery system of the
cells (tubular connections – like cars moving through tunnels
Review Question
Are endoplasmic reticulum found in prokaryotes?
No, prokaryotes do not have organelles that are membrane bound.
Cell Power plants Mitochondria and
Chloroplasts All cells need energy Mitochondria and chloroplasts both
have membranes Mitochondria are in all eukaryote
cells Mitochondria create useable energy
(ATP) from sugar using oxygen Only plant cells contain chloroplasts Plant cells create sugar using
sunlight, carbon dioxide, and water.
Cell Power plants Mitochondria and
Chloroplasts All cells need energy Mitochondria (2 or more mitochondrion)
Have 2 membranes: folded inner membrane and an outer membrane.
Where ATP is made Needs oxygen to perform cellular
respiration where glucose (sugar) is broken down to release energy in the form of ATP
ChloroplastsPlants and algae have this organelle that can covert sunlight energy, CO2 and H2O into glucose (C6H12O6)
Chloroplast means “green structure”.
Chlorophyll make chloroplasts green and is the compound that captures the light energy
Both mitochondria and chloroplasts have separate DNA.
Endosymbiotic Theory
Endo – inside, internal Symbiotic- living together, mutually
beneficial The Endosymbiotic Theory is an
explanation for the origins of mitochondria and chloroplasts.
The theory states that mitochondria and chloroplasts originated as prokaryotic cells that were eaten (endocytosis) and instead of being digested they survived and continued functioning
Lines of evidence for the Endosymbiotic Theory:
1. Mitochondria and chloroplasts are about the same size as bacteria (prokaryotes)
2. Mitochondria and chloroplasts are surround by two membranes
The inner membrane is thought to be the original bacterial cell membrane and the outer membrane created during endocytosis.
3. Mitochondria and chloroplasts contain a separate circular DNA which is duplicated when mitochondria and chloroplasts created.
The Cell’s Packaging Center- Golgi complex
The Golgi complex modifies and packages compounds such as lipids or proteins.
Golgi look like endoplasmic reticulum (ER) but are usually located closer to the cell membrane than ER.
Final modified products are enclosed in a piece of the Golgi membrane that pinches off to form a small compartment (vesicles) that transport the modified
The Cell’s Storage Centers
The cell’s storage centers are:VesiclesVacuoles
Vesicles are membrane covered compartments that are found in all eukaryotic cells
Vacuoles are membrane covered compartment that contain water and other liquids that help support the plant cells.
Special Vesicles
Contractile vacuoles are a type of vesicle that helps to control excess fluid in some unicellular organisms.Breath out – exhalation results from a
contraction of the diaphragm. Lysosomes are specialized vesicles that
contain digestive enzymes that get rid of waste materials and old cell parts, protect cells from foreign invaders, and helps digest food particles.
Endoplasmic reticulum
Nucleolus
Cytoplasm
DNA
Mitochondria
Cell membrane
Nucleus
Ribosomes
Golgi complex
Vesicles
Central Dogma
DNA to Proteins
Review1. (Organs or Organelles) ___________are
made up of various tissues that work together to perform a specific job.
2.The role of the cell’s ____________ (nucleus or mitochondria) is to release energy that can be used to power various cellular processes.
3. Unlike animal cells, plant cells have _____________(nuclei or chloroplasts)to capture energy from the sun.
4. DNA, the genetic material of a eukaryotic cell, is located in the cell’s ___________ (nucleus or ribosome).
Organs
mitochondria
chloroplasts
nucleus
Review5. Cells that have no membrane-covered
organelles are _____________ (prokaryotic or eukaryotic).
6. A part of the endoplasmic reticulum can pinch off and form a______________ (lysosome or vacuole), which contains digesting enzymes.
7. Which of the following statements is not part of the cell theory?a. The most basic component of any
organism is the cell.b. All cells originate from other cells.c. All cells have a nucleus and a cell
membrane.d. All living things are made up of one or
more cells.
prokayotic
lysosome
c. All cells have a nucleus and a cell membrane
8. A life scientist who observes the relationships between plants, animals, weather,and soil on a mountaintop is studying a(n) ________________a. community. c. ecosystem.b. population. d. organism.
9. Which of the following is not found in plant cells?a. lysosomes c. cell membraneb. ribosomes d. Golgi complex
10. Which of the following contain cellulose?a. all plant cell walls c. all eukaryotic cellsb. all mushroom cells d. some prokaryotic
cells
ecosystem (ecologist)
11. Which part of a cell manufactures lipids?__________________
a. nucleolus c. cell membrane
b. endoplasmic reticulum d. vesicles12. Materials that are to be released outside the
cell are transported to the cell membrane in a small compartment that has pinched off of thea. nucleus. c. rough ER.b. contractile vacuole. d. Golgi complex.
13. Which of the following is not a characteristic of bacteria?a. They are prokaryotes.b. Their DNA is one long, circular molecule.c. They have an endoplasmic reticulum.d. They have a cell membrane.
Endoplasmic reticulum