This segment provides a comprehensive overview of cell theory, prokaryotic vs. eukaryotic cells, and the detailed structure and function of major eukaryotic cell organelles (nucleus, mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus, peroxisomes), including their roles in cellular processes. next the cytoskeleton what's the most abundant thing in every cell in your body it's water what's the second most abundant proteins we have two types of proteins in the cell structural for the cytoskeleton and functional for enzymes pores channels pumps etc your cytoskeleton is a protein network who made it well ribosome again because it's a protein it helps the entire cell move cytokinesis it helps the cell divide during cell division mitosis or meiosis and it provides railroad tracks so that you can move your packages on the railroad the site the skeleton has gazillion other functions pause and review there are three types of cytoskeleton microfilament microtubules and intermediate filaments microfilaments actin how about microtubules alpha tubulin or beta tubulin and you find microtubules in cilia or Flagella first microfilaments remember my actin you start with monomers then they become polymers of G actin and then before you know it you have your actin filaments actin filaments have many functions including cell division these are your cleavage furrows that you studied in mitosis or meiosis for that matter next microtubules which have tubulin you have alpha tubulin and beta tubulin microtubules can provide the backbone for many structures if you want to make a centriole easy I'll give you nine triplets of microtubules and you will have a centriole but if you want a psyllium or if flagellum I'll give you nine doublets not triplets of microtubules plus two additional ones don't forget the story of kinase scene and dining defect is seen in a disease known as Cartagena's G zero and then you grow growth phase one and then you make DNA synthesis and then you grow again growth too and then mitosis or meiosis M phase somatic cells versus germ cells pause and review if I want to make another copy of my DNA this is called DNA replication which happens during the S phase of the cell cycle taking the DNA into RNA is transcription taking the RNA to proteins is translation with medicosis everything is a piece of cake where's the actual division happening in the M phase mitosis or meiosis that's why anything else is an interface G0 is for rest G1 is for growth because we're preparing for the S and the S phase you'll synthesize another copy of DNA hashtag replication then in the G2 you grow again and then in the M phase you have mitosis or meiosis pro meta Ana tello pro med anatello prophase metaphase anaphase telophase pause and review if the question asks you when does karyukinesis and cytokinesis take place the answer is M phase and here are some pearls for you pause and review cell types. You have permanent cells or stable or labile cells labile cells are always dividing permanent cells do not divide stable cells do not divide under normal circumstances but under crazy circumstances they can divide such as your liver permanent do not divide such as your neurons labile Always dividing such as sperm cells, gi cells your hair etc Stable cells are only under certain conditions like the liver If my cells are dividing like crazy with no check This is cancer. How does chemotherapy work? They stop or arrest cell division. What's the good news? We're killing cancer cells. What's the bad news? We're also killing some of your cells especially those who divide very rapidly. that's why with chemotherapy you get hair loss and diary cell cycle checkpoints to recognize the mutation or the error early on so that we can stop cell division otherwise we can get cancer. here is a comparison between the two. Please pause and review In mitosis you start with 2n and you give me two identical cell. each one is exactly identical to the parent cell also to N but in meiosis well it's called a reduction division because you start with 2N and you give me four cells each one is n H1 is not identical to the parent cell In fact each new offspring is half the parent. What are the phases pro? meta Ana-tello Pro. Before we're preparing meta everything is in the midline Anna, separate me and then what's your telos and purpose in life that's the last part during prophase there was condensation separation formation dissolution condensation of chromatin into chromosome terms separation of the centriole pairs formation of the mitotic spindle we're getting ready and dissolution of the nuclear membrane next metaphase everything is M we are in the midline thanks to the mitotic spindle which is basically microtubule and you can draw the line in the sand here and you get a mirror image also an M we are aligned in the midline anaphase separates me up split the centromere and separate the sister chromatid the kineto core is doing the pulling in telophase the mitotic spindle disappears we reform the nuclear membrane we form these cleavage furrows thank you microfilaments and then you separate the cell into two cells this is called cytokinesis meiosis popular belief fertilization is not when the sperm meets the ovum let's get technical it's when the sperm meets the secondary oocyte which is arrested in metaphase II fertilization is when the sperm meets the secondary oocyte which is arrested in metaphase II remember that oogenesis has two famous arrests pro phase 1 and metaphase 2 pro phase 1 and metaphase 2 pro phase 1 where the primary one with one oocyte is arrested waiting for the female to reach puberty how about the second arrest second arrest secondary oversight metaphase II everything here is two waiting for what for the sperm to go deep inside This segment details the five steps of fertilization (capacitation, acrosome reaction, polyspermy block, completion of meiosis II, and zygote formation), explaining each step's importance. It then follows the process through cleavage, blastulation, and the formation of the blastocyst, clearly differentiating the inner cell mass and trophoblast. the nucleus is in the head the mitochondria is in the middle piece here's the process of spermatogenesis thank you Sir Tolle cells we start with spermatogonia then primary spermatocyte secondary spermatocyte and then sperms let's make an ovum follicle stimulating hormone is going to simulate the follicle growth and then what and then the LH is gonna surge around day 14 and pew rupture the follicle release the oven the oven will go to the uterus the rest of the follicle will become luteal body which secretes progesterone if fertilization happens progesterone and estrogen will remain high but if it did not happen progesterone will drop estrogen will drop and the uterine lining will drop hashtag menses or menstrual bleeding pause and review These are This segment focuses on the mechanisms underlying the action potential, explaining depolarization (sodium influx) and repolarization (potassium efflux) in detail. It connects these processes to the resting membrane potential, emphasizing the roles of selective permeability and the sodium-potassium pump in maintaining the resting state. This segment concisely explains the contrasting roles of insulin (anabolic, building up) and glucagon (catabolic, breaking down) in glucose metabolism, highlighting their importance in fed and fasted states. It also introduces somatostatin as an inhibitor of both, providing a clear overview of key pancreatic hormones. think of it like a tree branching and differentiating example these are pluripotent stem cells in the bone marrow which gives you the blood cells. Do you remember the bilometer embryo? Yeah the inner cell mass is an example of totipotent stem cell because it can give you any part of the embryo. How about the mesoderm alone Such as mesodermal cell in the mesenchyme of your bone marrow they are pluripotent. Ah for example the bone marrow can only give you blood cells not every single imaginable cell do adults have stem cells yes they do in fact this is how you regenerate the stem cells of your skin or the basal layer or the stratum basalis in the alveoli they are type 2 pneumocytes please remember that type 2 pneumocytes have two functions function number one they are the stem cells of your lungs function number two is to release surfactant which is anti-surface tension The stem cell of your bone marrow is the hematopoetic stem cell which is pluripotent and the cell that regenerates sperms is spermatogonia apoptosis you protons, the more proton. Once you have the higher your hydrogen ion concentration and the lower your ph in your body. your metabolism secretes acids and carbon dioxide, which is technically an acid because it combines with water and give you carbonic acid. Who will get rid of this volatile acid? The lungs who is going to get rid of these non-volatile or fixed acids, the kidneys, if you metabolize more, you will end up with more acids. If you breathe more hyperventilation will lower your carbon dioxide in the blood. Conversely, hypoventilation will raise the carbon dioxide in your blood. Please pause and review loose Chetal yields principle. If your bicarbonate goes up and ph goes up. This is called metabolic alkalosis. If bicarbonate goes down and ph goes down. This is called metabolic acidosis. If carbon dioxide goes up, ph will go down. Respiratory acidosis if carbon dioxide goes down and ph goes up. This This segment focuses on the oxygen-hemoglobin dissociation curve, explaining the physiological shifts (right and left) caused by factors like exercise, altitude, and changes in pH and temperature. It clearly links these shifts to tissue oxygen delivery, making the complex concept easily understandable. This segment provides a clear comparison of innate and adaptive immunity, outlining the key players in each branch. It effectively explains the roles of B and T lymphocytes, antibody production, and the development of immunological memory, creating a solid foundation for understanding immune responses. crosses. We can map genes and chromosomes and get the recombination frequency which is proportional to the distance between two genes on a freaking chromosome. Using this theta or a combination frequency, you can deduce the order of genes on a chromosome, and we talked about this before Hardy-Weinberg equation, it's not hard. you just need to memorize two equations. More importantly, you need to understand what each letter refer to. For example, the P alone is the frequency of the dominant elite in a population. But the P squared is talking about an individual in that population. P alone is the tall allele. P squared is a tall individual. And here is an example that we did before just by giving you the first number, which is 70 percent. You can deduce all of the rest. Please pause and review and do it yourself. Evolution basics do not confuse natural selection with evolution. They are not identical. In fact, natural selection is a mechanism for evolution. There is the old theory and the modified modern synthesis theory We have different modes of natural selection could be stabilizing directional or disruptive when it comes to reproductive isolation. It could be pre--zygotic which prevents the zygote from forming in the first place or pose the exotic which allows as I go to be formed. However it's gonna be non-viable or sterile. An exam question will ask you about the mule. The mule is an example of hybrid sterility which is a post zygotic isolation pattern of evolution or many we have divergent parallel and convergent. we did it. You can This segment provides a comprehensive overview of blood components, including plasma proteins (albumin and globulins), and their functions. It then clearly explains the process of hemostasis, differentiating between primary (platelet plug formation) and secondary (coagulation cascade) mechanisms.