BSC 181 1st Edition Lecture 8Outline of Last Lecture I. Passive Membrane TransportII. ToxicityIII. Active Membrane TransportIV. Our Cells OrganellesOutline of Current Lecture II. Our Cells Organelles Continued III.The Cell Cycle Current LectureOur Cells Organelles Continued: Golgi Apparatus: the word to know when describing this organelle is “stacked,” because people describe it as stacked pancakes, or stacked what have you. This organelle is responsible for packaging and delivering proteins. The part of the Golgi Apparatus that isclosest to the nucleus is called the Cis face.Lysosomes: (lysis:means to break) you can think of the Lysosomes as the janitors of the cell, they contain digestive enzymes that help them digest bacteria, viruses, and toxins. They also break down nonuseful tissue, as well as break down bone. The reason they break down the bone is to release Ca2+ Peroxisomes: (Peroxi: means peroxide) you can think of these as the hazmat crew of the body, they break down harmful toxins in the bodyCytoskeleton: These help to keep our cells shape, these are made up of microtubules (micro:small) (tubules: means tube), microfilaments, and intermediate filamentsCentrioles: these are located near the nucleus, and during mitosis these centrioles organize the spindles. They also form the bases of cilia and flagella.Cilia: tiny hair like projections that are on the outside of the cell, they are responsible formovement, it’s like a moving sidewalk. They move substances in one direction across cellsurfaces, and they help move the eggs into the uterus. These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Flagella:only thing that has a flagella is a sperm cell, flagella is also needed for movementNucleus: the control center of the cell, this tells the cell which proteins need to be made as well as how many need to be made. It also contains nuclear envelope, nucleoli, and chromatin as well as our DNA.Nuclear Envelope: this is a double membrane layer that surrounds the nucleus and encloses the nucleoplasm.The membrane is semipermeable. The nucleoplasm is the fluid that is inside the nuclear envelope and surrounds the nucleus. The inside of the nuclear envelope is something called the nuclear lamina which is there to keep the shape of the nucleus. The outside of the envelope is peppered with ribosomes, because remember that the rough ER is positioned very close to the nucleus. Something else to remember is that the envelope has pores in it that allows bigger molecules into and out of the nucleus.Nucleoli: this is where the ribosomes are made, and the nucleolus exists within the nucleus (there can be more than one nucleoli in the nucleus) Chromatin/Chromosomes: Because chromatin (strands of DNA and histones) is so fragile, is will be turned into chromosomes during the cell cycle. They are the exact samematerials they have just changed shape. Chromosomes are just more condensed forms of chromatin.The Cell Cycle: Cell division occurs in order to help the body grow and help with tissue repair. There are three stages to the replication of a cell. Interphase, Mitosis, and Cytokinesis. Interphase is when the cell replicates its DNA. Mitosis is when the cell divides its nucleus, and cytokinesis is when the cell divides its cytoplasm. Interphase: this starts with the DNA helix unwinding which makes the two strands that where once together, apart. This exposes the two strands. Then the RNA primers in the body then give the signal to start the DNA synthesis. This jump starts DNA polymerase III(which is an enzyme that is attaches the nucleotides to the DNA chain). It basically is making two new strands to attach to the two strands that unwound from each other in the first step. When they connect they will have two completed DNA strands. One for the current cell, and one for the new cell.Mitosis: has four different parts to it, and this is when the cell divides the nucleus.Prophase, Metaphase, Anaphase, and Telophase.Prophase: this is wherechromatin condenses itself into chromosomes, all of the nucleoli disappear, and spindles are formed. (spindles will end up pulling the chromosomes to the corners of the cell)Metaphase:this is where the chromosomes line up in the middle of the cell with their centromeres in the exact middle of the cell. (centromeres are the middle of the chromosomes)Anaphase: This is where the centromeres split the chromosomes in half and they are pulled by the spindles to the opposite poles of the cell.Telophase: this is when everything “goes back to normal.” The two sets of chromosomes turn back into chromatin now that the cell has relaxed, the nucleoli reappear, and a new nuclear membrane is formed.Cytokinesis: this occurs after mitosis, and it is when the cell forms a cleavage furrow. It isalso where the body splits up all the organelles and the cytoplasm, and generally this ends cell