Bellwork What are the three main statements in the cell theory? Who was the first to discover the “cell”? Compare the Scanning Electron Microscope, Transmission Electron Microscope, and Scanning Tunneling microscope by illustrating the differences in images they capture.

Today! Standard B-2: The student will demonstrate an understanding of the structure and function of cells and their organelles. Objectives: I will be able to understand the functions of different cellular structures, along with illustrate each structure as it appears in the cell.

Types of Cells There are two broad groups of cells –Prokaryotes Do NOT have membrane-bound organelles –Eukaryotes DO have membrane-bound organelles Organelle –Structure within a cell that is surrounded by a membrane and has a specific function for cell survival

Eukaryotes Does have a membrane bound nucleus –DNA is bound within the nucleus Does Contain membrane- bound organelles Eukaryotes may be unicellular (algae and yeast) or multicellular (plants and animals)

Plasma Membrane (or Cell Membrane) Boundary of the cell Controls what goes in and out of the cell through the selectively permeable membrane –Keeps some things out and lets some things in Maintains cell’s homeostasis

Cell Wall Found outside the cell membrane Gives the cell added support and protection Made of the carbohydrate, cellulose This mesh of cellulose is porous and allows anything to pass through Plants, fungi, some protists and most bacteria (prokaryotes) have cell walls Animals DO NOT Cell Wall

Cytoplasm Cytoplasm is a semi- fluid material inside the cell It contains the molecules and organelles in the cell It is bound by the cell membrane

Nucleus and Nuclear Envelope Functions in the genetic control of the cell Contains the chromosomes which are composed of DNA The nuclear envelope is a membrane that –surrounds the nucleus –Regulates the materials that pass between the nucleus and the cytoplasm In eukaryotic cells (plants AND animals) * Important parts to know * *

Mitochondria This is the site of cellular respiration, a process that provides the cell with energy The “POWERHOUSE” The more energy a cell needs, the more mitochondria they may have –For example, a muscle cell would need more mitochondria than a bone cell because it requires more energy to do its job In eukaryotic cells

Chloroplast Contains the green pigment chlorophyll Chlorophyll absorbs energy from sunlight to convert carbon dioxide and water into sugar during photosynthesis Only found in plants and some algae

Ribosomes Ribosomes are the site of protein synthesis Can be found –floating free in the cytoplasm –or on the Rough Endoplasmic Reticulum In eukaryotes AND prokaryotes

Endoplasmic Reticulum (ER) ER is a complex, extensive network that transports materials throughout the inside of the cell Rough ER: –Has ribosomes attached Smooth ER: –Has no ribosomes In eukaryotes only

Golgi Apparatus Function: Modifies, collects, packages, and distributes molecules within the cell or outside the cell In eukaryotes

Lysosomes Small organelles containing digestive enzymes to break down food particles, worn out organelles, bacteria, and viruses into particles that can be used by the rest of the cell In eukaryotes

Vacuoles Sac-like structures that store materials such as water, salts, proteins, and carbohydrates Plants have one large vacuole that also helps give support to flowers and leaves Animal cell vacuoles are much smaller than plant cell vacuoles In eukaryotes animal plant

Cilia and Flagella Function: Helps to move the cell or its outer environment; some organisms use them to capture food. Cilia – short, numerous, hair-like projections that move in a wavelike motion –Animal cells and protists Flagella – longer projections that move in a whip-like motion –Animal cells, bacteria, and protists

Prokaryotes No true nucleus –DNA is not bound in a nucleus or arranged in chromosomes Do not have most membrane- bound organelles –They do have ribosomes for protein synthesis –They do not have mitochondria. They get their energy from the sun or from chemicals in the environment Many prokaryotes are unicellular This cell type includes all bacteria * Important parts to know * * * * Cytoplasm

Prokaryotes vs. Plants vs. Animals OrganelleProkaryotes Eukaryotes PlantsAnimals Plasma Membrane Cell Wall Nucleus DNA Mitochondria Chloroplasts Ribosomes

Prokaryotes vs. Plants vs. Animals OrganelleProkaryotes Eukaryotes PlantsAnimals Endoplasmic Reticulum Golgi Apparatus Lysosomes Vacuoles Cytoplasm Cilia or Flagella