CELL STRUCTURE AND FUNCTION
Prokaryotic vs. Eukaryotic Cells Karyotic- from Greek karyon meaning nut or kernel (referring to the nucleus here) Pro- Latin meaning for before Eu- Greek meaning for true
Prokaryotic vs. Eukaryotic Cells Prokaryote or Prokaryotic means before nucleus Eukaryote or Eukaryotic means true nucleus
Prokaryotic Cells Prokaryotic Cells are also known as bacteria!
Prokaryotic Cells (Bacteria) Have No Nucleus. Lack Internal Membranes (meaning no internal structures with membraneslike organelles). Genetic Material is a single circular DNA molecule floating in the cytoplasm. Always single celled & microscopic.
Prokaryotic Cells (Bacteria) Contain the following cell structures: Cell Wall Cell Membrane DNA Ribosomes Cytoplasm
Prokaryotic Cells (Bacteria) Prokaryotic cells are much smaller and less complex than Eukaryotic cells. They can reproduce much quicker than Eukaryotic cells however.
Beneficial Bacteria Not all bacteria are bad. Very few actually cause disease. Bacteria in and on us help: Provide nutrients: break down food, make vitamins. Keep away harmful microbes by filling spaces that would be filled by disease-causing bacteria. Help chemically break down dairy products to make yogurt and cheese, turn cucumbers to pickles, or to make soy sauce and vinegar.
Beneficial Bacteria In Ecosystems: Produce oxygen, recycle carbon, nitrogen, hydrogen and sulfur. Helps make minerals in the soil for plant growth. Bioremediation: break down pollutants (ex. Oil) Recycling and composting: biodegradable often means it can be broken down by bacteria.
Eukaryotic Cells Include all cells that have a nucleus.
Eukaryotic Cells Have a Nucleus Have Membrane Bound Organelles (tiny organs ) Genetic material in the form of linear (straight) chromosomes Includes both single celled and multi celled varieties. Almost all are still microscopic.
A Generalized Eukaryotic Cell Diagram although cells come in many shapes and sizes
Human cell size and shape comparison:
Types of Eukaryotic Cells: Animal Cells Plant Cells Both types have many of the same internal parts but there are also a few parts unique to either just plants or just animals. Let s start with the parts common to both types
Cell Parts Plants & Animals Have in Common: Cell Membrane Nucleus Ribosomes Cytoplasm Endoplasmic Reticulum Golgi Apparatus Vesicles Mitochondria Lysosomes
Cell Membrane: Surrounds the cell Controls movement of materials into and out of cell
Cytoplasm: cyto =something belonging to a cell. Fills space between cell membrane and nucleus. Maintains cell structure Where many chemical reactions take place.
Enable cells to move and divide. Cytoskeleton: Network of protein fibers crisscrossing the cytoplasm that constantly change to meet the needs of the cell. Give shape to the cell Anchors its organelles and serves as a track for them to move on.
Ribosomes: Make proteins for the cell Found in the cytoplasm or on the Rough Endoplasmic Reticulum (more on this later). Found in Eukaryotes and Prokaryotes
Cell Organelles: subcellular structures Structures specialized to perform distinct processes. Each is surrounded by or made up of membranes Only eukaryotes have organelles, prokaryotes do not.
Organelles involved in making proteins Ribosomes make proteins, but they need help from a number of organelles to do this: Nucleus Endoplasmic Reticulum Vesicles Golgi Apparatus
Nucleus: Proteins control the functions of the cell, but to create more proteins we need to start at the nucleus. Contains instructions to make proteins These instructions are in the form of DNA, Protects the DNA from dangers in the cytoplasm.
Nucleus: Includes the following 4 structures: Nuclear Envelope (Membrane): Controls movement into and out of the nucleus Nuclear Pore: Holes in the nuclear envelope which allow movement between the nucleus and cytoplasm.
Nucleus: Nucleolus: Dense region inside nucleus, where ribosomes are assembled Chromatin: Genetic Material (DNA) which is organized into structures called chromosomes during cell division.
Endoplasmic Reticulum (ER): Interconnected network of channels aids in movement of molecules inside the cell. Rough ER: Ribosomes found on surface. Proteins leave ribosome and enter into ER where they are modified. Smooth ER: No ribosomes on surface. Make lipids (fats) Break down drugs and alcohol.
Vesicles: Small membrane-enclosed sacs Transport molecules from place to place (ex. ER to Golgi Apparatus).
Golgi Apparatus: Stack of membraneenclosed spaces. Packages proteins for distribution within the cell and export out of the cell. Proteins come from endoplasmic reticulum.
Putting it all together Identify each of the following: A: B: C: D: E: F: D C A B E F
Other organelles: Mitochondria Vacuole Lysosomes Centrosomes Cell wall Chloroplasts Central Water Vacuole
Mitochondria: Chemical reactions here provide energy for cell. Converts food to usable energy for cell. Have their own ribosomes and DNA.
Lysosomes: Carry enzymes to destroy cellular waste. Break down damaged/worn out cell parts. Engulf/digest targeted molecules Defend cell from invading bacteria/viruses Membrane protects cell from enzymes.
Lysosomes: A cell can direct itself to die by creating a bunch of lysosomes and breaking them open inside of itself (apoptosis). This can happen if a cell is infected by a virus and also in normal development (how you lose your tail as an embryo).
Animal Cells contain all of the previous organelles plus: Centrioles: 2 cylindrical organelles (together called a centrosome) Part of the Cytoskeleton Produce microtubules that aid in moving chromosomes during cell division.
Plant Cells: contain all of the previous organelles (except centrioles) as well as: Cell Wall: Gives cells shape, support and protection. Found in algae, fungi and most bacteria too.
Plant Cells: contain all of the previous organelles (except centrioles) as well as: Chloroplast: Site of photosynthesis where chemical reactions create food for the cell. Also found in green algae.
Plant Cells: contain all of the previous organelles (except centrioles) as well as: Central Water Vacuole: Single, large water filled vacuole in the middle of the cell. Strengthen cells and provide support for plant. Contains toxins to harm plant predators, waste products and pigment for color (petals).
Gerenalized Animal Cell
Generalized Plant Cell
Unicellular (one) vs. Multicellular (many) Unicellular: Single-Celled Most common forms of life on Earth. Carry out all functions of Life. Bacteria Amoeba Paramecium
Unicellular (one) vs. Multicellular (many) Multicellular Larger organisms. Different cells have specialized functions, together making a complete organism. Human Rose Bush Mushroom
Inner Life of the Cell
Cell Structure/Function Vocab Prokaryotic Eukaryotic Cell Membrane Nucleus -Nucleolus -Chromatin Ribosomes Endoplasmic Reticulum -Rough vs. Smooth Golgi Apparatus Vesicles Mitochondria Lysosomes Centriole Cell Wall Chloroplast Water Vacuole Cytoplasm -Cytosol -Cytoskeleton Unicellular Multicellular