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Cellular Structure and Function. Section 1. Cell Discovery and Theory. Prokaryotic Cell. Prokaryotes are single-celled organisms that lack a nucleus and other internal compartments. They do not contain membrane-bound organelles. Steven P. Lynch. Cellular Structure and Function. Section 1.
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Cellular Structure and Function Section 1 Cell Discovery and Theory Prokaryotic Cell • Prokaryotes are single-celled organisms that lack a nucleus and other internal compartments • They do not contain membrane-bound organelles Steven P. Lynch
Cellular Structure and Function Section 1 Prokaryotic Cell • Prokaryotic cells includes all bacteria • Prokaryotes contain only the following structures: • Cell wall (peptidoglycan) • Plasma membrane • Genetic material as a single circular molecule of DNA • Ribosomes • Cytoplasm • Plasmid (Small circular piece of DNA that only some bacteria possess)
Cellular Structure and Function Section 1 Cell Discovery and Theory Prokaryotic Cell
Cellular Structure and Function Section 1 Eukaryotic Cell • More complex structure than prokaryotes • In addition to the prokaryotic structures, eukaryotes also have membrane bound organelles, including a nucleus
Cellular Structure and Function Section 1 Cell Discovery and Theory
Cellular Structure and Function Section 1 Cell Discovery and Theory Comparing Prokaryotic and Eukaryotic Cells The
Cellular Structure and Function Section 1 The Plasma Membrane Plasma Membrane • Thin, flexible boundary between the cell and its environment • Allows nutrients into the cell • Allows waste to leave the cell
Cellular Structure and Function Section 2 The Plasma Membrane Selective Permeability • The plasma membrane controls the movement of substances into and out of the cell. • The plasma membrane is selectively permeable, meaning it chooses what enters and leaves the cell
Cellular Structure and Function Section 2 The Plasma Membrane • The plasma membrane is composed of the phospholipid bilayer. • A phospholipid molecule is composed of a glycerol backbone, two fatty acid chains, and a phosphate group.
Cellular Structure and Function Section 2 The Plasma Membrane
Cellular Structure and Function Section 2 The Plasma Membrane Fluid Mosaic Model • The phospholipid bilayer allows other molecules to “float” in the membrane. Other Components • Proteins • Cholesterol • Carbohydrates
Cellular Structure and Function Section 2 The Plasma Membrane Proteins • Transmit signals inside the cell • Act as a support structure • Provide pathways for substances to enter and leave
Cellular Structure and Function Section 2
Cellular Structure and Function Section 3 Structures and Organelles Plant and Animal Cell Structures • Organelles are bodies within the cytoplasm that serve to physically separate the various metabolic reactions that occur within the cells • 1. Nucleus 7. Mitochondria • 2. Ribosomes 8. Chloroplasts • 3. Endoplasmic reticulum 9. Cytoskeleton • 4. Golgi Apparatus 10. Flagella & Cilia • 5. Lysosomes 11. Centrioles • 6. Peroxisomes 12. Vacuoles & Vesicles
Cellular Structure and Function Section 3 Structures and Organelles
Cellular Structure and Function Section 3 Structures and Organelles
Cells Nucleus • The nucleus is bounded by the nuclear envelope consisting a phospholipid bilayer, similar to the plasma membrane • The nucleus contains the DNA (deoxyribonucleic acid), the heredity information of the cell • The nucleus is the brain of the cell
Cells Nucleus • Also visible within the nucleus are one or more nucleoli, concentrations of DNA in the process of manufacturing the components of ribosomes
Cells Ribosomes • Ribosomes are manufactured in the nucleus and consist of ribosomal RNA and protein • Ribosomes are the site of protein synthesis • Ribosomes translate genetic information (DNA) into specific polypeptide chains & proteins
Endomembrane System • Composed of the same phospholipid bilayer as the cell membrane • They are membrane-bound organelles in eukaryotic cells • Similar to the organs of our bodies • Endomembrane systems only occur in eukaryotic cells
Endomembrane System • Components of the endomembrane system: • Nuclear envelope • Endoplasmic reticulum • Mitochondria (has 2 lipid bilayers) • Chloroplasts (has 2 lipid bilayers) • Golgi apparatus • Lysosomes • Vacuoles • Vesicles
Cells Endoplasmic Reticulum • The endoplasmic reticulum or ER, consists of stacks of flattened sacs of membrane • The best way to determine if the structure is the ER or Golgi apparatus is if it is connected to the nucleus. • ER is connected
Cells Endoplasmic Reticulum
Smooth ER Cells Endoplasmic Reticulum Rough ER When ribosomes are present, the ER is called the rough ER and provides Aids in protein synthesis Smooth ER, without ribosomes, is responsible for the synthesis of lipids and hormones.
Cells Golgi Apparatus • The Golgi apparatus • The Golgi modifies and package proteins and lipids into vesicles • The Golgi also produces lysosomes • Think of it as Fed Ex
Mitochondria • Mitochondria carry out aerobic respiration, a process in which energy (in the form of ATP) is obtained from organic molecules (glucose) • It’s the powerhouse of the cell • Mitochondria are found in both plant and animal cells • Since it converts food to usable energy (ATP), what type of cell would have a lot of mitochondria??
Chloroplasts • Chloroplasts are specialized organelles found in algae and plants that carry out photosynthesis, the process of capturing energy from sunlight and converting it into useable energy (carbohydrates)
Cells Chloroplasts
Chloroplasts • Chloroplasts contain chlorophylls, which are responsible for the green color of a plant and are the key light-trapping molecules in photosynthesis • Chloroplast are not found in animal cells. Why not??
Chloroplasts and Mitochondria • Add this to your notes!!!! • Both chloroplasts and mitochondria have their own circular DNA and ribosomes, just like bacteria • They also reproduce the same way as bacteria • This suggests that chloroplasts and mitochondria may have once been bacteria
Vacuoles & Vesicles • Vacuoles/ Vesicles are fluid-filled membrane bound bodies • They may contain food particles or digestive enzymes (found in lysosomes) • Transport substances throughout the cell • Release of cellular waste products
Cells Vacuoles & Vesicles • -Central vacuoles are large bodies that store water and occupies most of the interior of plant cells • -If the central vacuole runs low on water, the plant will begin to wilt • -The central vacuole in plants stores starch, pigments, and toxic substances
Lysosomes • Lysosomes are vesicles from the Golgi apparatus that contain hydrolytic digestive enzymes • They are the cell’s stomach • Lysosomes play an important role in: • Intracellular digestion such as breaking down food, cellular debris, and foreign invaders such as bacteria
Cells Lysosomes
Cells Cytoskeleton • The cytoskeleton is the internal structure of the cytoplasm and is involved in establishing the shape of the cell and coordinating movements
Cells Cytoskeleton
Cellular Structure and Function Section 3 Structures and Organelles Cilia • Short, numerous projections that look like hairs Flagella • Longer and less numerous than cilia • Create movement with a whiplike motion
Cellular Structure and Function Section 3 Table 7.1 Summary of Cell Structure Table 7.2 Summary of Cell Structure Table 7.3 Summary of Cell Structure
Cellular Structure and Function Section 3 Structures and Organelles Plant and Animal Cell Structures
cells: Cell Wall Chloroplasts Central Vacuole Structures only found in Plant Cells