Ch. 3 The molecule of cells The “A” TEAM Ch. 3 The molecule of cells

Great work! Period 2: Period 5: Period 1: Period 4: Danniel Barte Gia Difede Julian Garcia Amaya John Josh Poon Period 5: Belinda De Tullio Kyle Fuentes Joaquin Pazmino Anthony Silin Period 1: David Adams Shannon Amor Ahmari Avin Sean Byam Guiliana Chiquito Maria-Noelia Herne Harry Zarcadoolas Period 4: Emily Danzinger Eric Tobon

Chapter 4 A View of the Cell

Cellular Organization Tissue – group of cells functioning together. Organ – group of tissues functioning together. Organ System – group of organs functioning together. Organism – group of organ systems functioning together.

How did people get sick in the 15th century?

Redi and Spontaneous Generation Spontaneous generation: the idea that living organisms generate from nonliving matter, as inferred from rotting meat giving rise to maggots (fly larvae) Animation of Redi’s experiment

The History of the Cell The Cell The basic unit of an organism Discovery made possible by the invention of the microscope Scientists Animation

Microscopes and Cells Robert Hooke used the first compound microscope to view thinly sliced cork cells. Hooke was the first to use the term “cell”.

Microscopes and Cells 1600’s: Anton van Leeuwenhoek first described living cells as seen through a simple microscope.

Microscopes and Cells 1830’s: Mathias Schleiden identified the first plant cells and concluded that all plants made of cells. - Thomas Schwann made the same conclusion about animal cells.

Cell Theory: All organisms are made up of one or more cells. (Schleiden, Schwann, Hooke) The cell is the basic unit of all organisms. (Hooke, Leeuwenhoek) All cells come from other pre-existing cells. (Virchow)

Types of Microscopes Used Today: Light Microscope: uses a beam of light to produce image; LIVING tissue/organisms Compound Light microscope: multiple lenses (scanning, low, high power) Electron Microscope: uses an electron beam to produce image; more powerful than light; for NON-LIVING things Scanning (SEM): external surface of cells Transmission (TEM): internal structures of cells

Electron microscopes

Microscope Images Light microscope Scanning e- microscope Transmission e- microscope Scanning e- microscope

Everyday things under a scanning electron microscope

Why are cells so small? a. Efficiency:  smaller cells have larger surface area , smaller volume b. Specialization: Having numerous small cells permits specialization *The bigger the difference between surface area : volume ratio, the more efficient the cell. (Ex. 6:1 is better than 2:1)

Cube Surface area = L X W x 6 sides As an object increases in size, its volume increases, while surface area increases as well. Cube Surface area = L X W x 6 sides Volume = L X W X H As these cubes illustrate, the surface area to volume ratio of a small object is larger than that of a large object of similar shape This ratio limits how large cells can be

Goal: Students will be able to compare and contrast the structures of prokaryotes and eukaryotes; plant and animal cells. Plant Animal Eukaryotes (Protists, *Animal, Plant, Fungi) Prokaryotes (Archaebacteria, Eubacteria)

Two Basic Cell Types Prokaryotes Lacks internal compartments. No true nucleus. Most are single-celled (unicellular) organisms. Have circular DNA and ribosomes Have cell wall Examples: bacteria

A general prokaryotic cell

Two Basic Cell Types Eukaryotes Includes plant, animal, fungi and protists Has several internal structures (organelles). True nucleus: DNA is encapsulated Either unicellular or multicellular. unicellular example: yeast multicellular examples: most plants and animals

Eukaryotic Cell

Cell Organelles Internal structures of a cell that help it maintain functioning and homeostasis

(cell membrane) *ALL CELLS! Plasma Membrane Serves as a boundary between the cell and its external environment. Regulates the materials that pass in and out of the cell. Made up of 2 layers of phospholipids with proteins (phospholipid bilayer)

*ALL CELLS! Cytoplasm The jelly-like material that surrounds the organelles. Fluid space between organelles that help with movement of materials in the cell.

*ALL CELLS! Ribosomes Float around the cell but are mostly attached to the Rough E.R. (give the rough ER it’s “rough” or bumpy appearance) Center for making proteins – for enzymes, structural support, antibodies, etc.

ALL Prokaryotes; SOME Eukaryotes! Cell Wall Only found in certain cells - plants, bacteria, and fungi. Extra layer of support surrounding the plasma membrane Plant cell walls contain cellulose while fungi cell walls contain chitin.

ALL Prokaryotes; SOME Eukaryotes! Cilia Short, numerous, hair-like projections from the plasma membrane. Move with a coordinated beating action. Flagella Longer, less numerous projections from the plasma membrane. Move with a whiplike action.

*EUKARYOTIC CELLS ONLY! Nucleus Regulates all of the cell’s functions. Surrounded by a double-layered membrane (nuclear envelope) with large pores (nuclear pores) that allow only certain materials to pass in and out of the nucleus. Contains chromatin – long tangles of DNA wrapped around protein Nucleolus Found in the nucleus and responsible for ribosome production.

*EUKARYOTIC CELLS ONLY! Endoplasmic reticulum Folded membrane that acts as the cell’s delivery system of materials made in the cell. Smooth E.R. contains enzymes for lipid synthesis. Rough E.R. is surrounded with ribosomes for protein synthesis.

Smooth ER- Lipid synthesis

*EUKARYOTIC CELLS ONLY! Golgi bodies (or Golgi apparatus) A series of flattened sacs where newly made lipids and proteins from the E.R. are repackaged and shipped to the plasma membrane for export out cell or to parts inside the cell where they are needed.

*EUKARYOTIC CELLS ONLY! Vacuoles A sac of fluid surrounded by a membrane used to store food, fluid, or waste products. Plants- one large, central vacuole that help maintain cell shape and smaller vacuoles around rest of the cell. Animals- small vacuoles throughout the cell

*EUKARYOTIC CELLS ONLY! Lysosomes Bubbles of phospholipids containing digestive enzymes Can fuse with vacuoles to digest food, or can digest worn cell parts, or microorganisms invading the cell. Also known as “suicide sacs” because they can also destroy the whole cell. Tay- Sachs disease

*EUKARYOTIC CELLS ONLY! Mitochondria Produce the energy for the cell in the form of ATP. Also known as the “powerhouse of the cell”. Has a highly folded inner membrane (cristae).

*EUKARYOTIC CELLS ONLY! Chloroplasts Found in plant cells and some protists. Transforms light energy into chemical energy which is stored in food molecules; where photosynthesis takes place. Contain chlorophyll – a green pigment that traps light energy and gives plants their green color.

*EUKARYOTIC CELLS ONLY! Cytoskeleton A network of thin, fibrous materials that act as a scaffold and support the organelles. Microtubules – hollow filaments of protein. Microfilaments – solid filaments of protein.

Types of Cytoskeleton

*EUKARYOTIC CELLS ONLY! Centrioles made of protein. play a role in splitting the cell into two cells during mitosis (cell division process) found in animal and fungi cells.

Flagella nucleolus Nucleus Chromosomes Rough Endoplasmic reticulum Ribosomes Rough Endoplasmic reticulum Microtubule Mitochondrion Picture adapted from Access Excellence’ rescource center: http://www.accessexcellence.org/RC/ Golgi apparatus Centrioles Cilia

Review Questions Which of these is not a type of cell? a) bacterium; b) amoeba; c) sperm; d) virus A prokaryotic cell would NOT have which of these structures? a) ribosome; b) nucleus; c) cell membrane; d) cell wall Ribosomes are cellular structures involved in ____. a) photosynthesis; b) chemosynthesis; c) protein synthesis; d) carbohydrate synthesis The earliest microscopes used to image the specimens. a) high energy electron beams; b) interatomic forces; c) low energy electron beams; d) light Plant cells have ___ and ___, which are not present in animal cells. a) mitochondria, chloroplasts; b) cell membranes, cell walls; c) chloroplasts, nucleus; d) chloroplasts, cell wall The ___ is the membrane enclosed structure in eukaryotic cells that contains the DNA of the cell. a) mitochondrion; b) chloroplast; c) nucleolus; d) nucleus The mitochondrion functions in ____. a) lipid storage; b) protein synthesis; c) photosynthesis; d) DNA replication; e) ATP synthesis Which of these cellular organelles have their own DNA? a) chloroplast; b) nucleus; c) mitochondrion; d) all of these Answers 1.D 2.c 3.b 4.c 5.d 6.d 7.d 8.e 9.d

Goal: Students will be able to compare and contrast the structures of prokaryotes and eukaryotes; plant and animal cells. Plant Animal Eukaryotes (Protists, Animal, Plant, Fungi) Prokaryotes (Archaebacteria, Eubacteria)