Organelles and the Cell PDF

8/27/24, 8:24 PM Platform | Study Fetch Organelles and the Cell (00:00 - 00:14) Introduction to the topic of cells and organelles Organelles in Cells (00:14 - 00:28) Organelles are tiny structures within the cytoplasm...

8/27/24, 8:24 PM Platform | Study Fetch Organelles and the Cell (00:00 - 00:14) Introduction to the topic of cells and organelles Organelles in Cells (00:14 - 00:28) Organelles are tiny structures within the cytoplasm of cells that perform specific roles Both eukaryotes and prokaryotes have organelles Lesson Overview (00:28 - 00:43) Discuss organelles in both animal and plant cells Discuss organelles unique to animal and plant cells The Cell and its Components (00:43 - 00:55) The cell is the basic functional unit of all living things Cells are organized into larger structures like tissues Organelles in Cells (00:55 - 01:07) Cells have many organelles and units that make them up Animal and plant cells share some organelles and have others that are unique The Cytosol (01:07 - 01:21) The cytosol is the fluid that makes up the interior space of the cell It is important to maintain specific ion levels in the cytosol The cytosol is where diffusion takes place and contains all the other organelles The Cytoskeleton (01:21 - 01:47) The cytoskeleton is made up of three types of fibers: Intermediate filaments (e.g. keratin) Microtubules Microfilaments https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bde8ab287f54e41f2ae/document?go=note 1/7 8/27/24, 8:24 PM Platform | Study Fetch The cytoskeleton provides structural support and helps shuttle things around the cell Microtubules (01:47 - 02:38) Microtubules are made of tubulin They play a role in cell division Proteins called kinesin and dynein bind to microtubules and act as "railroads" to shuttle things around the cell, especially in neurons Synaptic Vesicle Transport (02:38 - 03:05) In neurons, synaptic vesicles need to be transported from where they are manufactured in the cell body to the synapses The microtubule "railroads" facilitate this transport of synaptic vesicles Cytoskeleton and Cell Organelles (00:03:05 - 00:03:17)Microtubules Serve as "superhighways" or "roads" for kinesin and dynein motor proteins to transport cargo around the cell (00:03:17 - 00:03:30)Microtubules Made up of large tubulin tubes Discussed in more detail in other videos Microfilaments Made of actin Important for muscle contraction, along with myosin (00:03:30 - 00:03:41)Microfilaments Actin filaments are made of two filaments connected together Form longer structural cables that run through the cytoplasm (00:03:41 - 00:03:54)Nucleus The information archive of the cell Stores all the information that makes up the cell (00:04:06 - 00:04:25)Nuclear Pore An important structure in the nucleus Excludes certain things from entering the nucleus Facilitates the shuttling of things like transcription factors into the nucleus (00:04:25 - 00:04:35)Nuclear Pore Allows proteins like RNA polymerase to be shuttled into the nucleus so they can perform their function (00:04:35 - 00:04:49)Nuclear Pore Crucial in helping important molecules get into the nucleus and excluding things that could damage the DNA https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bde8ab287f54e41f2ae/document?go=note 2/7 8/27/24, 8:24 PM Platform | Study Fetch (00:04:49 - 00:05:00)Histones Structural proteins around which DNA is wrapped Form "beads on a string" that condense the chromatin (00:05:00 - 00:05:27)Chromatin Condensation Chromatin starts as individual "beads on a string" Condenses into higher and higher order structures Ultimately forms the condensed chromosomes during cell division (00:05:27 - 00:05:38)Nucleolus Located within the nucleus Site where ribosomes are made (00:05:38 - 00:05:56)Ribosomes Have two major components made up of RNA Ribosomes are made in the nucleolus Ribosomes and Protein Synthesis (00:05:56 - 00:06:07) Cells require a large number of ribosomes to meet their protein synthesis demands Ribosomes are produced in the nucleolus Telomeres (00:06:07 - 00:06:20) Telomeres are structural elements at the end of chromosomes Telomeres prevent degradation of chromosomes during cell division Each cell division results in some loss of telomere length Telomeres act as "caps" to allow for lossless information transfer between cells Cells can only divide a certain number of times before telomeres are depleted and cell division stops Mitochondria (00:06:37 - 00:07:22) Mitochondria are the "powerhouses" of the cell Mitochondria are where oxidative respiration and ATP synthesis occur Mitochondria have an outer membrane, an inner membrane, and an intermembrane space The inner membrane and intermembrane space allow for the formation of electrochemical gradients that drive ATP synthesis Endoplasmic Reticulum (ER) (00:07:49 - 00:08:33) The ER is part of the endomembrane system of the cell mRNA transcripts are shuttled from the nucleus to the ER https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bde8ab287f54e41f2ae/document?go=note 3/7 8/27/24, 8:24 PM Platform | Study Fetch Ribosomes assemble on the rough ER and synthesize proteins Transmembrane proteins are synthesized and embedded in the ER membrane Secreted proteins are also synthesized in the ER Protein Trafficking (00:08:33 - 00:08:59) Transmembrane proteins are synthesized and embedded in the ER membrane Secreted proteins are also synthesized in the ER and then transported out of the cell The Endomembrane System and Organelles The Endoplasmic Reticulum (ER) and Nuclear Envelope (00:08:59 - 00:09:17) Many proteins need post-translational modifications, which requires the ER to shuttle them elsewhere The ER is contiguous with the nuclear envelope, a bilayer membrane surrounding the nucleus The Nuclear Envelope and Lamins (00:09:17 - 00:09:34) The inner nuclear envelope layer is made up of a protein called lamins Lamins are important structural proteins that give the nuclear envelope its integrity The Golgi Apparatus (00:09:34 - 00:09:53) The Golgi apparatus has a cis face and a trans face The cis face receives incoming transport vesicles from the ER The ER sends incomplete proteins that need further post-translational modification to the Golgi Protein Modification and Packaging (00:09:53 - 00:10:19) The Golgi apparatus is where further packaging and post-translational modification of proteins occurs This is important for the proper function of many proteins in the body Modified proteins are then sent out of the trans face of the Golgi to perform their roles Peroxisomes (00:10:19 - 00:10:32) Peroxisomes are membrane-bound sacs within the cell https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bde8ab287f54e41f2ae/document?go=note 4/7 8/27/24, 8:24 PM Platform | Study Fetch They contain enzymes that deal with metabolic components, often using oxygen Lysosomes (00:10:32 - 00:10:57) Lysosomes and peroxisomes are similar, but contain different types of enzymes Lysosomal enzymes tend to be acidic and break down long biological polymers These are typically substances the cell has taken up from the outside environment Peroxisomes vs. Lysosomes (00:10:57 - 00:11:20) Peroxisomes break down metabolic products using reactive oxygen species Lysosomes break down long chains of sugars, amino acids, and other substances taken in from the outside Animal vs. Plant Cells (00:11:34 - 00:11:57) Animal cells have lysosomes and centrosomes Plant cells have a central vacuole, chloroplasts, and a cell wall Lysosomes (00:11:57 - 00:12:08) Lysosomes are enclosed membrane-bound organelles in the cytoplasm They contain enzymes, typically acidic, that break down substances Cellular Organelles and Structures Acidic Environment and Centrioles (00:12:08 - 00:12:20) The acidic environment helps the cell break down many of the things it has taken in from its environment that it needs to break down Centrioles will be discussed more in the cell division section Microtubule Organizing Center (00:12:20 - 00:12:30) The cell has 3 triplets of microtubules, 9 in total This microtubule organizing center serves as the hub for the "railroads" throughout the cell https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bde8ab287f54e41f2ae/document?go=note 5/7 8/27/24, 8:24 PM Platform | Study Fetch Role in Cell Division (00:12:30 - 00:12:42) The microtubule organizing center organizes the spindle during cell division to ensure the chromosomes end up on either end of the cell Plant Cell Structures (00:12:42 - 00:13:01) Plant cells have a central vacuole, which is the major storage hub Plant cells also have chloroplasts, where the main photosynthesis takes place Photosynthesis in Plant Cells (00:13:01 - 00:13:18) The chloroplasts in plant cells use light energy from the sun to generate the energy the cell needs for metabolism Differences in Cell Coats (00:13:18 - 00:13:39) Animal cells have a basement membrane and a more complex tissue structure The cells need proteins that can bind to the extracellular matrix to hold onto the scaffold Extracellular Matrix in Animal Cells (00:13:39 - 00:13:59) The extracellular matrix in animal cells is made of collagen, fibronectin, and proteoglycans This provides structural support and water sequestration Extracellular Matrix in Plant Cells (00:13:59 - 00:14:37) Plant cells have a thick, carbohydrate-based extracellular matrix in addition to the cell wall This provides rigidity and structural strength, made of materials like pectin, glycans, and cellulose The extracellular matrix is attached to the plasma membrane Comparison of Animal and Plant Cell Coats (00:14:52 - 00:15:06) Animal cells have a cell membrane with proteins that bind to the external extracellular matrix Plant cells have a cell wall/extracellular matrix structure, rather than just a cell membrane https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bde8ab287f54e41f2ae/document?go=note 6/7 8/27/24, 8:24 PM Platform | Study Fetch https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bde8ab287f54e41f2ae/document?go=note 7/7