Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First,...

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Cells!

Transcript of Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First,...

Page 1: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cells!

Page 2: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Have we always known about cells?

No, they are too small to see with just our eyes.

First, we needed the invention of the microscope to see things this small.

Page 3: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Compound microscope Specimen is magnified as light passes through several lenses.

Page 4: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Robert Hooke: English Scientist:

observed cork with a microscope. He thought the box-like structures he saw

looked like jail cells…

Page 5: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 6: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Anton Van Leewuenhooke:

Discovered bacteria, protizoa, and other microscopic organisms.

Page 7: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 8: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Electron Microscope

Some things are so small light waves totally miss them. Waves from electrons are used to “see” these very small objects.

Page 9: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Blood as seen with compound microscope

Blood seen with electron microscope

Page 10: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Pollen

Foot of house fly

Staple in Paper

Moth scales

Page 11: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cell Theory:

Cells are the basic unit of life.

All cells come from pre-existing cells.

Page 12: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Exceptions to the cell theory

The First Cell could not have arisen from a pre-existing cell.

Viruses are not composed of cells but do contain genetic material.

Although considered organelles, Mitochondria and Chloroplasts contain genetic material and can reproduce inside a cell.

Page 13: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Two types of cells

Prokaryotic cells: Lack membrane bound structures such as a nucleus, mitochondria and chloroplasts.

Pro = before Karyotic = nucleus

Examples: Bacteria

Page 14: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Notice… no nucleus, no mitochondria, no chloroplasts

Page 15: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Eukaryotic cells

Have membrane bound structures such as a nucleus, mitochondria…

Eu = true Karyotic = nucleus

Examples: all other cells

Page 16: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cell Size Prokaryotic/bacteria: very small… 1 to 10

micrometers Eukaryotic: bigger… from 10 to 100

micrometers Chicken egg cell = 6 cm (the whole egg) Nerve cell = 1 meter long Human egg cell = 100 micrometers Red blood cell = 9 micrometers Skin cell = 20 micrometers

Page 17: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

White blood cell and bacteria

Page 18: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cell size and surface area

Length of side (cm)

1 cm 3 cm

Total surface area (cm2)

Total volume (cm3)

Surface are to volume ratio

Page 19: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cell size and surface area

Length of side (cm)

1 cm 3 cm

Total surface area (cm2)

1cm2 x 6 sides = 6cm2

9cm2 x 6 sides = 54 cm2

Total volume (cm3)

1x1x1 = 1cm3 3x3x3 = 27cm3

Surface are to volume ratio

6:1 54:27 = 2:1

Page 20: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Structural heirarchy: Atoms: elements = carbon, hydrogen Molecules: water, glucose Organelles: nucleus, ribosome Cells: muscle cell, blood cell Tissue: fat tissue, bone tissue Organ: Stomach, lung Organ system: digestive system Organism: us

Page 21: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cell Organelles 1. Plasma membrane (cell membrane)

– Function: selectively permiable, keeps contents of cell in

– Structure: phospholipid bilayer

– In both plant and animal cells

Page 22: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cytoplasm Function: site of many chemical

reactions, gives cell its shape

Structure: gel like substance made of 80% water.

Page 23: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Nucleus Function: the control center for all cell

functions. It controls growth and cell division

Structure: Envelope surrounding DNA

Page 24: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Nucleolus Function: Makes ribosomes

Structure: Dense body inside the nucleus

Page 25: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Endoplasmic Reticulum Function: Aids in the assembly and transport

of proteins and lipids.

Structure: a network of folded membranes that form channels from the cell membrane through the cytoplasm to the nuclear membrane

Page 26: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Ribosome: Function: assembles proteins

Structure: small dot like structures found on the E.R. or in cytoplasm

Page 27: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Mitochondria Function: break down carbohydrates

and sugars, making energy from the food we eat

Structure: 2 membranes, inner membrane folded, has own DNA

Page 28: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Golgi Complex Function: Packages materials for

release from the cell. Structure: Stacks of flattened

membranes and vesicles budding off

Page 29: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Lysosome Function: disposal and recycling units of the

cell. (little stomachs)

Structure: Membrane bound structures containing enzymes necessary for digesting certain material in a cell

Page 30: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Vacuole: Function: stores food, water, and waste

Structure: fluid filled sac (plant cells have large vacuoles)

Page 31: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Centriole: Function: aids in animal cell division

Structure: nine sets of three fused microtubles arranged in an open star shape and located just outside of the nucleus

Page 32: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Chloroplast Function: turns the sun’s energy into

food (photosynthesis) Structure: 2 membranes, oval, green

Page 33: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cell Wall Function: support and structure for cell.

Structure: cellulose fibers

Page 34: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cell Membrane

Phospholipid bilayer

Page 35: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Selective Permeability

The following substances can easily pass through the cell membrane….

Lipid soluble substances

Small stuff – Glucose, oxygen, carbon dioxide, ions

Page 36: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Passive Transport: no energy required

Diffusion: movement of molecules from a high concentration to a low concentration

Page 37: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Facilitated diffusion– Membrane proteins help molecules pass

through the cell membrane.

Page 38: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Osmosis: Movement of WATER molecules from a high to a low concentration.

Page 39: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Active Transport: requires energy (ATP)

Movement of molecules from a Low to a High concentration.

Facilitated transport:– Some membrane proteins require energy

to move molecules through the cell membrane.

Page 40: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Pinocytosis: cell drinking

Phagocytosis: cell eating

Page 41: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 42: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 43: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 44: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 45: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 46: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 47: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 48: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 49: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.
Page 50: Cells!. Have we always known about cells? No, they are too small to see with just our eyes. First, we needed the invention of the microscope to see things.

Cell Organelle Lab These pictures are what you should

have seen in the microscope…

Cork

Elodea

Cheek cells

Onion skin