A&P Review for Chapter 3: Cells

Review for Chapter 3: Cells 1. Pinocytosis- a form of endocytosis one of the 3 types. The membrane engulfs droplets of liquid (cell drinking). Moves fluid. Referring to small fluid droplets inside of the cell. EX: let's say we want to get a fluid filled sac of extracellular fluid (which is everything that floats around the cell) so the cell membrane produces individualization and then can put a cell membrane around it which is pinocytosis. 2. Phagocytosis- membrane engulfs solid particles (cell eating). If the cell wants to ingest a particular particle that is not fluid it is called phagocytosis. And that is almost the exact same as pinocytosis but here we are bringing in a particle. You will see that the macrophage (located in the immune system) does a lot of phagocytosis. 3. Homeostasis- maintenance of a stable environment 4. Chromatin- the extremely long molecules of DNA are complexed with proteins to form fibers called chromatin. Carries information to synthesize proteins. Consists of the 46 chromosomes. 5. Chromosomes- 46. Contains the DNA wound around many proteins. 6. Cytoplasm- consists of networks of membranes suspended in cytosol. It = cytosol+organelles. It also contains the cytoskeleton which is a supporting framework of protein rods and tubules. 7. Cytosol- the fluid portion of the cytoplasm. 8. What are the major regions of the cell? Nucleus, cytoplasm and cell membrane. 9. What are cell membranes made of? What are cell membranes characteristics? Cell membranes are made up of a phospholipid bilayer. Lipids and proteins. Also has cholesterol which stabilizes the membrane, and helps keep it impermeable to water-soluble solutions. Membrane proteins- that have many functions; pores, enzymes, channels, and receptors. Cell contact and identification. Carbohydrates- cell recognition and interaction, self markers. 10. What are the 4 levels of organization of a protein? 1. Primary- amino acid sequence. Each oblong shape in the polypeptide chain represents an amino acid molecule. The whole chain represents a portion of protein molecules. 2. Secondary- pleated or twisted structure formed by hydrogen bonding between non adjacent amino acids. The polypeptide chain of a protein molecule is often pleated or twisted to form a coil. Dotted lines represent hydrogen bonds. R groups are highlighted. 3. Tertiary- unique 3 dimensional folded shape of the protein. The pleated and coiled polypeptide chain of a protein molecule folds into a unique 3D structure. 4. Quaternary- structure formed by some proteins, when 2 or more polypeptide chains are connected to become 1 protein. Two or more proteins often different may combine to form a single larger protein molecule. 11. Know differences between DNA and RNA. Which has U? Which has T? Which has ribose vs. deoxyribose? DNA is deoxyribonucleic acid. It is the genetic material and stores instructions on how to produce proteins that function as: enzymes, blood proteins, structural proteins of muscle and connective tissue, antibodies, and cell membrane components. It is 2 nucleotide chains twisted into a double helix. Each nucleotide consists of a 5-C structure (deoxyribose), a phosphate, and a nitrogenous base (adenine, guanine, cytosine, or thymine). Hydrogen bonds hold the bases together. The bases pair specifically (A-T and C-G) this is called complementary base pairing. DNA wraps around histone proteins to form chromosomes. Histone protein helps compact DNA and regulate genes. It is made up of: adenine, cytosing, guanine and thymine. Containing the T. RNA is single strands of nucleotides. Each nucleotide contains: ribose, phosphate base (adenine, guanine, cytosine and uracil) Containing the T. Complementary base pairing in RNA: A-U, C-G. Much shorter than DNA. 12. Where is DNA found? What are the base pairing roles? DNA is found in the nucleus. The base pairing roles are known as complementary base pairing and they are A-T and C-G. 13. Know the phases of the cell cycle (mitosis) in order and what is happening in each phase? The phases of the cell cycle are: 1. Interphase- very active period in cell cycle. Where the cell grows and maintains normal functions. The cell replicates genetic material (DNA) to prepare for mitosis(nuclear division)). Cell synthesizes organelles, membranes, and biochemicals to prepare for cytokinesis (division of cytoplasm). There are 2 phases of this: 1. S (synthesis) phase: DNA is replicated during this phase. 2. G1 and G2 (growth or gap) phases: structures other than DNA are replicated and cell grows during them. This is where all other structures are being replicated. 2.Mitosis- produces 2 daughter cells from an original somatic cell. It is the division of the nucleus. There are 4 stages. 1. Prophase - chromatin condenses to form chromosomes, centrioles move to opposite sides of cytoplasm, nuclear envelope and nucleolus disperse. 2. Metaphase- spindle fibers from centrioles attach to chromosomes and align them midway between centrioles. Complete aligning of chromosomes on the center lining of the cells. 3. Anaphase- chromosomes separate (away) and move in opposite directions toward centrioles as the spindle fibers shorten. 4. Telophasechromosomes return to chromatin structure, nuclear envelope forms around each chromosome set, and nucleoli become visible. Where the chromosomes return to their normal structure wound around proteins and the cells start to pull away for cytokinesis. 3. Cytokinesis- cytoplasmic division. Begins during anaphase. Continues through telophase. Contractile ring of actin filaments pinches the cytoplasm in half. Newly formed cells will have identical DNA, may have slightly different size and number of organelles. The 2 cells divide so we can have 2 identical brand new cells. They have the same structures. Made up of 46 chromosomes. 14. During the cell cycle, when is DNA duplication? Where is DNA stored in the cell? DNA is stored in the nucleus. DNA duplication is during interphase and is during the S (synthesis) phase. 15. Be sure to know definitions, similarities and differences between simple and facilitated diffusion. Simple diffusion- the movement of atoms, molecules, or ions, from region of higher concentration to a region of lower concentration. Occurs due to constant motion of atoms, molecules, and ions. Only substances that the cell membrane is permeable to: oxygen, carbon, dioxide, and other lipid-soluble substances. This is a passive process and no ATP (energy) is required. Dissolving a sugar cube in water is an example. 16. Be sure to know all the organelles within a cell and what the major functions and nicknames are. Ribosomes- composed of protein and RNA. free in cytoplasm or fixed on the rough endoplasmic reticulum. Provide structural support and enzyme activity to link amino acids in protein synthesis. Primary role of protein synthesis. Endoplasmic reticulum- membrane bound sacs, canals, and vesicles. Tubular support system. Rough ER contains ribosomes, conducts protein synthesis. Smooth ER does not have ribosomes; conducts lipid synthesis. The primary role of the rough ER has ribosomes on it and that is the site of protein synthesis in our body. Vesicles- membranous sacs. Store or transport substances. Golgi apparatus- sacs of flattened membranous sacs. Refines, packages, and delivers proteins made on the rough ER. Mitochondria- membrane-bound fluid-filled sacs. House chemical reactions that extract energy from nutrients (cellular respiration, which produces ATP) Called the powerhouse of the cell. It is a membrane bound organelle and has its own membrane surrounding it which is also a phospholipid bi layer that exists very similar to the membrane. Has some DNA inside. Lysosomes- small membranous sacs. Contain enzymes that digest proteins, carbohydrates, nucleic acids, bacteria, debris, worn out cell parts. Garbage disposals of a cell. Peroxisomes- membranous sacs similar to lysosomes. Contain enzymes that digest lipids, alcohol, and hydrogen peroxide. Nucleuscontains genetic material and controls cell activities. Nuclear envelope- porous double layer membrane. Separates nucleoplasm from cytoplasm. Nuclear pores allow passage of certain substances. Nucleolus- dense body of RNA and protein. Site of ribosome production. Chromatin- consists of cell chromosomes, each containing DNA wound around proteins. Stores information for protein synthesis. 17. Where are ribosomes made? Ribosomes are made in the nucleolus. 18. Is vesicle an organelle? Yes. 19. Know the major forms or passive vs. active transport we discussed. Physical (passive) processes- does not require ATP (energy). The major forms are: diffusion, facilitated diffusion, osmosis, filtration. Physiological (active) processes: requires ATP. The major forms are: active transport, endocytosis, exocytosis, and transcytosis. 20. Know what happened to a RBC when placed in the 3 concentrations of solutions. Osmotic pressure is the ability of osmosis to generate enough pressure to lift a volume of water (movement of water). Osmotic pressure increases as the concentration of impermeable solutes increase. - Isotonic solution: same osmotic pressure. Cells in an isotonic solution have no net gain or loss of water - Hypertonic solution: higher osmotic pressure. Cells in a hypertonic solution lose water (cells shrink and shrivel) - Hypotonic solution: lower osmotic pressure. Cells in a hypotonic solution gain water (cells swell and burst).