CellsCells

The Basic Unit of LifeThe Basic Unit of Life

Cytology:

The Study of Cells

TermsTerms• Cell – the basic unit of life; all living things

are made of cells• Cell wall – firm structure outside of plant

cells made of cellulose that support the cell• Chlorophyll – green pigment that traps light

energy used for photosynthesis• Chloroplast – organelle in plant cells where

photosynthesis takes place

• CiliaCilia – short, hair-like structures some cells have for movement

• Compound light microscopeCompound light microscope – instrument that magnifies an object by using light and lenses

• CytoplasmCytoplasm – cell’s ‘fluid’

• Electron microscopeElectron microscope – instrument that uses magnets and electrons to magnify very small objects

• EukaryoteEukaryote – a cell with a nucleus

• FlagellaFlagella – a whip-like ‘tail’ some cells have for movement

• GolgiGolgi – membrane sacs that receive and repackage proteins

• MitochondriaMitochondria – organelle that produces energy for the cell by breaking down glucose (sugar)

• MulticellularMulticellular – an organism made of many cell that are specialized

• NucleusNucleus – organelle that contains the genetic code (DNA)

• OrganOrgan – a group of tissues that function together• OrganelleOrganelle – a structure found in eukaryotic cells

that performs a specific function; surrounded by a membrane

• Organ systemOrgan system – a group of organs that function together

• Plasma membranePlasma membrane – the boundary between the cell and it’s environment; controls what gets in or out

• ProkaryoteProkaryote – a cell without a nucleus

• RibosomeRibosome – an organelle that produces proteins for the cell

• Rough endoplasmic reticulum – produces proteins for the cell

• Smooth endoplasmic reticulum – produces lipids for the cell

• TissueTissue – a group of cells that function together

• UnicellularUnicellular – a cell composed of only one cell; Paramecium, amoeba

• VacuoleVacuole – sac-like organelle that stores water, food or poisons

ACOS - 4ACOS - 4

• Describe the similarities and differences of cell organelles using diagrams and tables including-

– cell membrane, cell wall, nucleus, ribosome, smooth endoplasmic reticulum, rough endoplasmic reticulum, Golgi body, vacuole, chloroplast, and mitochondria

ACOS - 4ACOS - 4

• Classify organisms as prokaryotic or eukaryotic

• Identify and define similarities and differences between the 5 kingdom and 6 kingdom classification systems

ACOS – 5

• Identify cells, tissues, organs, organ systems, organisms, populations, communities, and ecosystems as levels of organization in the biosphere

– Recognize that cells differentiate to perform specific functions• Ex. Ciliated cells produce movement, nerve

cells conduct electrical charges

ACOS - 2• Describe cell processes necessary for

achieving homeostasis, including active and passive transport, osmosis, diffusion, exocytosis, endocytosis

– Identify functions of carbohydrates, lipids, proteins, and nucleic acids

– Compare reactions of plant and animal cells in isotonic, hypotonic and hypertonic solutions

ACOS - 2

– Explain how surface area, cell size, temperature, light and pH affect cell activities

– Apply the concept of fluid pressure to biological systems• Blood pressure, turgor pressure, bonds,

strokes

Cell TheoryCell Theory• Most important tool to cytology:Most important tool to cytology:

Microscopes ACOS 1Microscopes ACOS 1

• Light microscope - uses lenses to magnify lightlight through the object

• Electron microscope - uses magnets to focus a beam of electrons through the object

Types of MicroscopesTypes of Microscopes

• Light:• Uses light and lenses• Only magnifies 1500 x• Live

• ElectronElectron • Uses magnets and

electrons to magnify• Magnifies 1,000,000 x• Not alive

Cell Theory ACOS - 4Cell Theory ACOS - 4

• 1665: Robert Hooke: looked at cork

• Called little spaces ‘cells’

Anton Van Leeuwenhoek, 1678; Looked at pond water, teeth scumSaw one-celled ‘animicules’ (bacteria)

Spirochete

Cell Theory ACOS – 4

• Schleiden – botanist– ‘plants are made of cells’

Cell Theory ACOS – 4• Schwann – zoologist/physician

– ‘animals are made of cells’

Cell Theory ACOS – 4• Virchow – physician

– ‘cells come from other cells’– ‘cells cause disease’

Main Parts of a Eukaryotic Cell:Main Parts of a Eukaryotic Cell:

1. Cell membrane (plasma membrane)

2. Cytoplasm and organelles

3. Nucleus

Cell MembraneCell Membrane• Controls (regulates) what enters and exits

the cells

Cell Membrane

Cytoplasm and Organelles

• Cytoplasm = ‘ cell’s fluid’; mostly water

OrganellesOrganelles

Ribosomes = manufacture proteins

OrganellesOrganelles

• Rough Endoplasmic reticulum

• Rough ER• Folded membrane that forms a

network of tubes and compartments + ribosomes to make proteins

Smooth Endoplasmic Reticulum

• Endoplasmic reticulum that does not have ribosomes

• Manufactures

– Lipids,

– Steroid hormones

OrganellesOrganelles

Golgi body - Golgi body - membrane sacs that store and repackage proteins

• Some proteins are ‘shipped out’ of the cell for use by other cells

– Hormones; insulin

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Quiz: Cells 1

Which device would be used to observe ribosomes?

– Magnifying lens; light microscope, electron microscope, petri dish

Which device would be used to transfer small amounts of liquids?

- Petri dish, pipette, beaker, graduated cylinder, flask

Which device would be best to measure mass?

balance; graduated cylinder, flask, pipette

Which structure manufactures proteins for the cell?

smooth ER; rough ER; cell membrane; cytoplasm

Which structure transports proteins around the cell?

ribosomes; smooth ER; cytoplasm; rough ER

OrganellesOrganelles

Vacuoles - sacs that temporarily store:

– Food

– Water

– Poisons (plants)

Energy Organelles:

1. Mitochondria

• Cellular respiration - sugar (glucose) is broken down to release energy

• Might = energy

• Mighty mitochondria

Energy Organelles:

2. Chloroplasts

• Contain chlorophyll

• Photosynthesis

Chloroplasts:

• Capture the sun’s energy and use it to:

• Photosynthesis -

• Change carbon dioxide (CO2) and water (H2O) into glucose (food)

Cytoplasmic streaming

CO2

Photosynthesis

H2O

Nucleus

• Nucleus: membrane-bound organelle towards the center of the cell

1. Enclosed by a membrane (membrane bound)

2. DNA = determines inherited traits

Movement OrganellesMovement Organelles• Cilia – hair-like projections on the

outside of some cells for movement

– Short

– ‘oars’

– Paramecium

– Lungs

Cilia

Paramecium

Paramecium Stentor

Vorticella

Movement Organelles

• Flagella

• Whip like ‘tail’

• One or only a few

• Movement

EuglenaEuglena

Euglena-Flagella

Prokaryotic or Eukaryotic

• ProkaryoticProkaryotic• No nucleus

• No organelles

• Bacteria

• EukaryoticEukaryotic• Nucleus

• Organelles

• All other organisms

Bacteria = ProkaryotesBacteria = Prokaryotes

EukaryoteEukaryote

ACOS – 5

• Hierarchy of life – life becomes increasingly complex

Cells

Organs

Tissues

Organ Systems

Populations

Organisms

Communities

Hierarchy of organization

Ecosystems

Cell

Tissue

Organ Organ System

Organism

Plant Cells

• Cell Walls = outside covering

• Cellulose • Strength

• Support

• ‘Square’ shape

Plant CellsPlant Cells

• Chloroplasts = contain chlorophyll for photosynthesis

• Capture sun’s energy

Plant CellsPlant Cells• Large water vacuoles = storage of water

• ‘Water balloons’

• Keeps plants cells ‘full’

Animal Cells:

• Membranes

• Ribosomes

• ER

• Vacuoles

• Golgi• Mitochondria

• Nucleus

• Cilia (some)

• Flagella (some)

Plant CellsPlant Cells

• Cell Membrane

• Ribosomes

• ER

• Vacuoles

• Golgi

• Mitochondria

• Nucleus

• Cell WallCell Wall

• ChloroplastsChloroplasts

• Large water Large water vacuolesvacuoles

• No cilia, flagella

• Animals:– Membrane– Ribosomes– ER– Vacuoles– Golgi– Mitochondria

– Nucleus

• Plants:Plants:– MembraneMembrane– RibosomesRibosomes– ERER– VacuolesVacuoles– GolgiGolgi– MitochondriaMitochondria– NucleusNucleus– Cell wallCell wall– Water vacuoleWater vacuole– ChloroplastsChloroplasts

Cell Energy

Respiration

Photosynthesis

PhotosynthesisPhotosynthesis

• Photosynthesis – process of combining carbon dioxide and water by capturing the energy from light

• Light energy is stored in the bonds of carbon and hydrogen in the glucose

Photosynthesis

6 CO2 + 6 H2O C6H12O6 + 6 O2

Carbon dioxide

Water Glucose Oxygen

Photosynthesis

6 CO2 + 6 H2O C6H12O6 + 6 O2

Carbon dioxide

Water Glucose Oxygen

Reactants Products

Photosynthesis

• What happens to the glucose?

• Used immediately by the plant for energy

– Growth, reproduction (fruits)

• Leftover glucose is stored by the plant as starch (roots, stems, leaves)

• Animals eat the plants (and the glucose and starch); food chain

Food Chains• Energy flows from the:

• Light, to the…

• Plants, to the…

• Herbivores, to the …

• Carnivores, to the …

• Scavengers.

• Carbon dioxide returns to the air, back into the plants

Respiration

• Process of producing energy

– Combine oxygen with glucose

• Cells use the energy for:

– Movement

– Mitosis

– Active transport of substances out of the cell

– Making proteins and DNA

C6H12O6 + 6 O2 6 CO2 + 6 H2O

Reactants Products

Glucose Oxygen Carbon dioxide Water

Plants and Algae

Photosynthesis

C6H12O6 + 6O2

Respiration

6CO2 + 6H2O

Animals and Fungi

Aquatic Food Chains