1) How many bacteria cells will it take to make a line across a dime? 17,000
Do you think a real dime has bacteria on it? Why or why not? Bacteria live almost every where on Earth
How small are cells? • Unit of measure is micrometer. ( µm) • One millionth of a meter. • 1 micrometer (some bacteria) • 1000 micrometer (some plant and animal cells)
Microscope • Led to the discovery of cells and development of the cell theory. • 1000 times • Treated with dyes to make structures in cell easier to see.
Scanning electron microscope (SEM)Transmission electron microscope(TEM) Electrons not light, are used to produce images . They can magnify up to a million times.
SEM produces a three dimensional image. • TEM looks like a thin slice of the bacteria cell.
Cryo-electron microscope can magnify specimens one million times Dime = 12 miles wide
Cells are diverse • Diversity of sizes and shapes. • Boundary or cell membrane that lets things in or out of cell. • Gelatin like substance called cytoplasm. Most of the work is carried here.
Two separate cell categories Prokaryotic cells are usually simple organisms. No separate compartment for generic material. No organelles. • Eukaryotic cells are usually multicellular organisms • Generic material in nucleus. • About 10x larger than prokaryotic.
Cell Wall The sound that you hear when a carrot is broken is half is the sound of the cell wall breaking. Only plant cells have a cell wall.
Structures that process information Ribosomes Help translate that information. Located in the cytoplasm and the endoplasmic reticulum. Use the information to build important molecules called proteins. • Nucleus • Largest organelle • Contains information for cell functions
Organelles that provide energy • Plants • Get their energy from the sun. • Chloroplasts use the suns energy to make sugar.
Animal cells do not contain chloroplast and thus cannot get energy from the sunlight. • Animal cells get energy (food) from the sugar that plant cells have stored. • Eating plants or by eating animals that have eaten plants.
Both plant and animals must be able to use energy to do work. • The energy is made available by organelles found in all eukaryotic cells. • Mitochondria are the organelles that use oxygen to get food from processing food.
Organelles that process and transport • Endoplasmic reticulum • System of twisting and winding membranes • Some contain ribosomes (which make proteins) • Manufactures parts of the cell membrane • Part of the cellular transport system • Some can form vesicles which transport materials processed materials to an organelle called the Golgi apparatus
Golgi apparatus takes the materials manufactured by the ER and finishes processing them.
Organelles for storage, recycling and waste • Cells store water, sugar and other materials which they use to function. • Cells also store waste materials until they can be removed. • Plants have vacuoles which are sacs that hold these materials. • Plants have large vacuoles that which store water. • Animal cells don’t have vacuoles but have lysosomes, which break down old used cell parts.
Review Questions Page Questions 1-6. These questions and answers will be part of the 3-4 notes