STM 007 General Biology 2nd Quarter Exam Study Guide PDF

STM 007: GENERAL BIOLOGY 1 2nd QUARTER EXAM STUDY GUIDE MODULE 12: GAMETOGENESIS (SPERMATOGENESIS & OOGENESIS) Gametogenesis - the formation of sex cells or reproductive cells also known as gametes. It happens in primary sex organ called gonads. The male gonad is called testis while in female...

STM 007: GENERAL BIOLOGY 1 2nd QUARTER EXAM STUDY GUIDE MODULE 12: GAMETOGENESIS (SPERMATOGENESIS & OOGENESIS) Gametogenesis - the formation of sex cells or reproductive cells also known as gametes. It happens in primary sex organ called gonads. The male gonad is called testis while in female is ovary which both contain primordial germ cells. Primordial germ cell - the common origins of spermatozoa and oocytes, these cells are responsible for the production of gametes. Spermatogenesis - the formation of sperm cells located in the seminiferous tubules of male gonad. Seminiferous tubules - the site for germination, maturation and transportation of the sperm cells within the male testes. Spermiogenesis - is the transformation of spermatids into functional spermatozoa. ▪ The spermatogenesis produced four haploid cells (4n) at the end of the process. Oogenesis - is the formation of ovum located in the female gonad called ovary. Oogonium - the immature female germ cell. Polar body - is a small haploid cell that is formed concomitantly as an egg cell during oogenesis, but which does not have the ability to be fertilized. ▪ At the end of the process, oogenesis produced haploid cells (n) or one ovum.  MODULE 14: THE STRUCTURE AND Cholesterol - keep cell membrane from COMPONENTS OF PLASMA becoming stiff by preventing MEMBRANE phospholipids from being too closely packed together Plasma Membrane - thin semi- permeable membrane that surrounds the cytoplasm of a cell FUNCTIONS: ▪ Protect the integrity of the interior of the cell. ▪ Serve as a base of attachment for the cytoskeleton. ▪ Regulate the cell growth through the balance of endocytosis and exocytosis. Endocytosis - a process by which cells absorb external material by engulfing it with the cell membrane. Exocytosis - an energy-consuming process that expels secretory vesicles out of the cell membranes into the extracellular space. Glycolipids - located on cell membrane surfaces and have a carbohydrate sugar chain attached to them - helps in recognizing other cells of the body 2 Structural Components of Plasma / Cell Membrane: 1. Cell Membrane Lipids 2. Cell Membrane Proteins Peripheral membrane proteins Phospholipids - are lipid bilayer which is semi-permeable, allowing only certain - are exterior to and connected to the molecules to diffuse across the membrane by interactions with membrane. other proteins. Integral membrane proteins - portions of these transmembrane proteins are exposed on both sides of the membrane Structural proteins - help to give the cell support and shape Receptor proteins - help cells communicate with their external environment through the use of hormones neurotransmitter, and other signaling molecules. Transport proteins - transport molecules across cell membranes through facilitated diffusion Glycoproteins - help in cell to cell communications and molecule transport across the membrane ▪ The main difference between glycolipid and glycoprotein is that glycolipid is a carbohydrate- attached lipid whereas a glycoprotein is a carbohydrate- attached protein.  MODULE 15: PASSIVE TRANSPORT Equilibrium – the uniform distribution MECHANISM: SIMPLE AND molecules FACILITATED DIFFUSION Osmosis - a type of diffusion where molecules of water are moving from a region of high-water concentration to a Membrane transport - refers to the region of less water concentration by collection of mechanisms that regulate the passing through a semi-permeable passage of solutes such as ions and small membrane. molecules through biological membranes, which are lipid bilayers that contain proteins embedded in them. 2. Facilitated Diffusion Types of membrane transport can be - a process whereby a substance grouped into passive transport and passes through a membrane with an active transport. aid of an intermediary or a facilitator 1. Passive Transport can be; - The facilitator is an integral ▪ Simple Diffusion membrane protein that spans the ▪ Facilitated Diffusion width of the membrane 2. Active Transport can be; ▪ Ion Pumps ▪ Exocytosis ▪ Endocytosis PASSIVE TRANSPORT: (doesn’t need an energy to transport molecules) 1. Simple Diffusion - small non-charged molecules or lipid soluble molecules pass between the phospholipids to enter or leave the cell - moving from areas of high concentration to areas of low concentration ▪ Oxygen and carbon dioxide and most lipids enter and leave cells by simple diffusion. Diffusion occurs when particles spread. They move from a region where they are in high concentration to a region where they are in low concentration, it happens when the particles are free to move.  MODULE 16: ACTIVE TRANSPORT What is Bulk/Vesicular Transport? MECHNISM: SODIUM AND Most molecules, including proteins, are POTASSIUM, PUMP and too large to pass directly through BULK/VESICULAR TRANSPORT membranes. Instead, large molecules are loaded into small membrane-wrapped containers called vesicles. Vesicles are Active Transport constantly forming - especially at the - the movement of molecules across a cell plasma membrane, the Endoplasmic membrane from a region of their lower Reticulum, and the Golgi. Once formed, concentration to a region of their higher vesicles deliver their contents to concentration destinations within or outside of the cell. - requires the assistance of a type of Vesicular transport is the predominant protein called a carrier protein, using mechanism for exchange of proteins and energy supplied by ATP or Adenosine lipids between membrane-bound Triphosphate to affect the transport. organelles in eukaryotic cells. Active transport is the process by which 2 Types of Vesicular Transport: dissolved molecules move across a cell 1. Endocytosis membrane from a lower to a higher 2. Exocytosis concentration. In humans, active transport takes place during the digestion Both processes are active transport of food in the small intestine. processes, requiring energy. Carbohydrates are broken down into simple sugars such as glucose. 1. Endocytosis - is the process of capturing a substance or particle Type of Active Transport: from outside the cell by engulfing it with the cell membrane. 1. Sodium-Potassium Pump - Sodium is Na+ while Potassium is Examples: K+ Phagocytosis - is the type of endocytosis - It requires ATP to move ions against where an entire cell is engulfed. their concentration gradients. - Pumps 3 sodium ions (Na⁺) out of - known as cellular eating, occurs the cell and 2 potassium ions (K⁺) when the dissolved materials enter into the cell per cycle. the cell. Pinocytosis - is when the external fluid is engulfed - known as cellular drinking, occurs when the plasma membrane folds inward to form a channel allowing dissolved substances to enter the cell Receptor-mediated endocytosis - occurs when the material to be transported binds to certain specific molecules in the membrane. 2. Exocytosis - describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell. - occurs when a cell produces substances for export, such as a protein, or when the cell is getting rid of a waste product or a toxin. -