Ch 4: Cell Structures Essential Questions: How is the structure of the cell related to function? How do cell malfunctions result in pathologies? Practice Quiz: https://www.goconqr.com/en-US/p/5996944-Ch-4---Cell-Structure-and-Function-quizzes

Studying Cells Normal PAP *Review the different types of microscopes and how they are used to view cells.* CYTOLOGY = study of cells. CYTOTECHNOLOGIST = professional who studies cells and determines if cells are abnormal; PAP test Abnormal PAP

Cell Theory All living things are composed of cells Robert Hooke, “Micrographia” Anton van Leeuwenhoek, “Animalcules” Schleiden and Schwann All living things are composed of cells Cells come from other cells The cell is the basic unit of life

Cell Size

Cell Size Surface area and volume are limiting factors for cell size. As cells grow too large, the membrane can’t transport enough materials.

Prokaryote Cells Does not contain a membrane bound nucleus; smaller than eukaryotic cells Domain: Bacteria & Archaea All cells have: Cytosol, Plasma membrane, ribosomes, DNA

Eukaryotic Cells Main Features Membrane-bound nucleus with chromosomes Various organelles that perform specific functions. Liquid interior is the cytoplasm (cytosol)

Endosymbiosis Theory Provides a possible explanation for the origin of eukaryotic cells, particularly the mitochondria and chloroplasts.

Plasma Membrane Phospholipid bilayer with embedded proteins

The Nucleus Nuclear Envelope Nucleoplasm Nucleolus - makes ribosomes Chromosome (chromatin, DNA) - information storage

Ribosomes Site of protein synthesis Floats in cytoplasm and found attached to endoplasmic reticulum mRNA provides the code to build a chain of amino acids

Mitochondria CELLULAR RESPIRATION “Powerhouse” of the cell Provide energy in the form of ATP Specifically, they are responsible for CELLULAR RESPIRATION Has mitochondrial DNA that is separate from the cell’s DNA. Endosymbiosis theory suggests that eukaryotes evolved from prokaryotes and that the mitochondria was once a free-living prokaryote.

What happens if your mitochondria don’t work? Mitochondrial Disease Video Why is mitochondrial disease so devastating to children? Consider the mitochondria have their own DNA separate from the parental DNA. How could you cure this disease? Check out this video: https://youtu.be/GcubrH6HRnk 1. Inner Membrane 2. Outer Membrane 3. Cristae 4. Matrix

Peroxisomes Lysosomes Small organelles that carry out oxidation reactions Enzymes within them safely break down hydrogen peroxide. Lysosomes Found in animal cells, known as the “garbage disposal” because they break down substances (digestion)

GM2 ganglioside enters the nerve cell as a source of food GM2 ganglioside enters the nerve cell as a source of food. Lysosomes contain an enzyme, Hex-A that digests GM2. Children with Tay-Sachs lack Hex-A, so the GM2 builds up within the cell and eventually kills it. Ellie’s Story | Cure Tay-Sach’s Foundation

Vesicles and Vacuoles Used for storage and transport. Vesicles can fuse with the membrane and transport materials out of the cell. Plants have a large CENTRAL VACUOLE

Centrosomes (Centrioles) Move chromosomes during cell division, builders of cytoskeleton *Animal cells only

Chloroplasts Plant cells only - site of photosynthesis Like the mitochondria, also has its own DNA

Cell Wall Only found in plant cells Rigid structure made of peptidoglycan and cellulose This make plants difficult to digest

I am a reticulated python I am a reticulated python. Ask me what I have to do with the endoplasmic reticulum. The word “reticulum” means net.

Endomembrane System A group of organelles that work to process, package and secrete proteins. Ribosomes make the proteins Endoplasmic reticulum transports proteins (smooth vs rough) Golgi Apparatus packages & exports (like a post office)

The Cytoskeleton Network of fibers that gives support and structure to the cell: Microfilaments / Microtubules / Intermediate Filaments (maintain shape) Actin / Movement Cilia and Flagella function in movement

The Big Picture

a. ________________ b. ________________ c. _________________ d.  _________________ e.  _________________ f.  __________________ g.  __________________ Pg 81 g. f.