General Biology Reviewer for 1st Quarter (1st Semester) Exam PDF

General Biology Reviewer for 1st Quarter (1st Semester) Exam Abiogenesis - Life came from nonliving things. Biogenesis - Life came from living things. Francesco Redi - disproved the spontaneous generation through his 3 Jar experiment. Louis Pasteur - credited for disproving spontaneous generation....

General Biology Reviewer for 1st Quarter (1st Semester) Exam Abiogenesis - Life came from nonliving things. Biogenesis - Life came from living things. Francesco Redi - disproved the spontaneous generation through his 3 Jar experiment. Louis Pasteur - credited for disproving spontaneous generation. The discoveries made by Hooke, Leeuwenhoek, Schleiden, Schwann, Virchow, and others led to the formulation of the cell theory. na The discoveries made by Hooke, Leeuwenhoek, Schleiden, Schwann, Virchow, and others led to the formulation of the cell theory and this describes the properties of cells. (1) All living things are composed of one or more cells; (2) (3) Lu The cell is the basic unit of life; and All cells arise from pre-existing cells. v in ar M CELL MEMBRANE - (contains phospholipid bilayer) It separates the cell from the external environment & controls the passage of organic molecules, ions, water, oxygen, and wastes in and out of the cells. CYTOPLASM - The gelatinous liquid that fills the inside of a cell, it provides the structure of the cell & site of metabolic reactions NUCLEOLUS - An area inside the nucleus of a cell that is made up of RNA and proteins and kung saan ginagawa ang ribosomes NUCLEUS - Cell organelle that houses DNA and directs synthesis of ribosomes and protein RIBOSOMES - an intracellular structure that is made of RNA and protein and the site of protein synthesis in the cell. MITOCHONDRIA – generate most of the chemical energy needed to power the cell's biochemical reactions (ATP IS PRODUCED - Adenosine Triphosphate) PEROXISOMES - Are organelles that sequester diverse oxidative reactions & play important roles in metabolism, reactive oxygen species, detoxification, and signaling. VESICLES - Help transport materials that an organism needs to survive and regulate waste materials. May power din mag absorb and destroy TOXIC substances and pathogens to prevent cell damage and infection. VACUOLES - It is a membrane-bound organelle. In animal cells, vacuoles are generally small na and help sequester waste products. In plant cells, vacuoles help maintain water balance. (TURGOR PRESSURE ang tawag sa pressure in this organelle kapag PLANTS) CENTROSOME - A cellular structure involved in the process of cell division (nag duduplicate ang centrosome then mag separate away from each other) CHLOROPLAST - site of photosynthesis. Lu CELL WALL - A rigid non living permeable wall and enables and supports the cell of most plants, bacteria, fungi, and algae. SMOOTH AND ROUGH ENDOPLASMIC RETICULUM - A large, dynamic structure that marami ginagawa sa cell like calcium storage, protein synthesis, and lipid metabolism GOLGI APPARATUS - A cell organelle that helps process and package proteins and lipid in molecules, especially proteins na maeexport na out of the cell CYTOSKELETON - Maintains cell shape, secures their position, allows cytoplasm and vesicle to move within, and enables unicellular organisms to move independently. v FLAGELLA - A flagellum is primarily a motility organelle that enables movement and chemotaxis ar CILIA - Cilia are short, hair like appendages extending from the surface of a living cell. WEEK 2: CELL TYPES AND MODIFICATIONS M There are two kinds of organisms according to their cell structure, the prokaryotes and eukaryotes. PROKARYOTIC AND EUKARYOTIC CELLS PROKARYOTES PRO = Before KARYO = Nucleus (kernel or nuts) - are single celled organisms that lack a membrane bound nucleus (lahat ng prokaryotes walang nucleus mitochondria, and all other organelles.) - Prokaryotic Cells  > includes bacteria and archaea (single celled organisms) kaya nilang mag survive in hostile environments this pertains to organisms in a form of bacteria called extremophiles (living in extreme environment) > some prokaryotes are multicellular in nature but mostly unicellular. > Shapes are cocci (round), bacilli (rod shaped) or spirilla (helical) EUKARYOTES EU = True KARYO = Nucleus (kernel or nuts) - are organisms with cells that contain membrane bound nucleus and other membrane bound organelles. (meron lahat nung na discuss sa module 1) na - Eukaryotic Cells > has a nucleus that contains genetic material (DNA) enclose by a nuclear envelope. > also unicellular in nature example is protozoa. Other eukaryotes are multicellular organisms such as plants. animals and fungi. Tissue Modifications Lu TISSUE - same cells that fused or combined together and have the same function. 1. Apical modification - top part or cell’s surface. 2. Lateral modification - side part of the cell in - Gap junctions (for communication) - Tight junctions - serves as barrier for molecules and pathogens - Adhering junctions - anchors or binds the cell surface. 3. Basal modification - bottom part of the cell v EPITHELIAL TISSUE - This type of tissue is commonly seen outside the body as coverings or as linings of organs and cavities. ar - found in our skin, blood vessels, urinary tract or a protective covering in some organs. - acts as a barrier between the inside and outside of the body and protects it from viruses. (external protection) - prime function is to absorb and secrete M CONNECTIVE TISSUE - Found in between other tissues everywhere in the body and has LOOSE and DENSE tissues BLOOD - made up of plasma CONNECTIVE TISSUE PROPER (CTP) - made up of loose connective tissue DENSE CONNECTIVE TISSUE - such as tendons and ligaments, is composed largely of densely packed fibers. Much of the fibrous tissue of connective tissue is composed of collagen, a protein material of great tensile strength, that can act as cushion for the bones. Note: When a ligament is torn or damaged in case of sprain, the responder must first elevate the foot and apply cold compress to the wounded area. na CARTILAGE - characterized by collagenous fibers embedded in chondroitin sulfate. SKELETAL - striated voluntary movements Lu BONE - mineralized connective tissue made by bone-forming cells called osteoblasts MUSCLE TISSUE - These tissues are composed of long cells called muscle fibers CARDIAC - striated with intercalated disk for synchronized heart contraction (involuntary) SMOOTH - not striated involuntary in NERVOUS TISSUE - These tissues are composed of nerve cells called neurons NEURONS - the basic functional unit of the nervous system (cannot undergo mitosis) v NEUROGLIA - a variety of non- nervous cells that insulate neuron membranes and serve various supportive functions. ar Week 3: Cell Cycle - Mitosis Cell cycle enables a living thing to continue its existence by multiplying itself in controlled and systematic processes. M CHROMOSOMAL FORMATION - passed from parents to offspring, DNA contains the specific instructions that make each living type unique - refers to how chromosomes form through cell division - 23 PAIRS OF CHROMOSOMES MUST BE MADE CELL DIVISION - It involves the distribution of identical genetic material or DNA to two daughter cells. INTERPHASE: (the growth period in the cell cycle) CHECK POINT - a critical control point in the Cell Cycle where stop and go ahead signals can regulate the cell cycle. G1 CHECKPOINT - the Restriction Point & ensures that the cell is large enough and has sufficient energy to divide - Kapag hindi keri at maliit masyado ang cell ay pupunta ito sa G0 (fun fact: halos lahat ng cells in our body ay nasa G0) S PHASE (Synthesis Phase) - DNA replication occurs where the nucleus becomes larger with twice the amount of DNA. - nagkokopyahan na ng chromosomes G2 CHECKPOINT - Ensures that DNA replication in S phase has been successfully completed. na PROTEIN CHECKPOINTS: Mitosis Promoting Factor PROTEIN KINASE – catalyze phosphorylation PROTEIN CYCLIN - binds to kinase PMAT PROCESS: Lu MITOSIS - is nuclear division the process by which the nucleus divides to produce two new nuclei 1. PROPHASE - is the preparatory stage, during prophase, centrioles move toward opposite sides of the cell & while doing so the nuclear membrane starts to disappear in (chromosomes are not yet visible) 2. PROMETAPHASE - the nuclear membrane disappears and the chromosomes are now visible (late prophase). The centrioles will release spindle fibers to attach to the kinetochores of the chromosome (early metaphase) v 3. METAPHASE (ALIGNED IN THE MIDDLE) - is when chromosomes become arranged so that their centromeres become aligned in one place called metaphase plate. - METAPHASE CHECKPOINT (if spindle fibers are correctly attached to centromere) ar 4. ANAPHASE (AWAY OR SEPARATION OF CHROMOSOMES) - is initiated by the separation of sister chromatids. 5. TELOPHASE (COMPLETE MIGRATION) - is when daughter chromosomes complete their migration to the opposite poles. Spindle fibers detach and nuclear membrane M reappears. 6. KARYOKINESIS - Nuclear division and the actual “start” of a cell's physiological division. 7. CYTOKINESIS - is the physical process that finally splits the parent cell into two identical daughter cells. This is where a CLEAVAGE FURROW appears. WEEK 4: MEIOSIS MEIOSIS (more complex than Mitosis) - Reduces the amount of genetic information. While mitosis in diploid cells produces daughter cells with a full diploid complement, meiosis produces haploid gametes or spores with only one set of chromosomes.  - RECONSTITUTE Diploid Complement - Contains 2 Successive Division (PMAT 1) PROPHASE 1 - Identical to Prophase in mitosis. - Has been subdivided into five substages: 1. Leptonema/Leptotene - condensation of chromosomes 2. Zygonema/Zygotene - synapsis between homologous chromosome 3. Pachynema/ Pachytene - Crossing over (the reason why organisms are genetically diversified) 4. Diplonema/Diplotene - dissolution of synaptonemal complex na 5. Diakinesis - dissolution of nuclear membrane Note: Recombination is the exchange of traits METAPHASE 1 (CHROMOSOMES GO TO MIDDLE ULIT) -The spindle apparatus is completely formed and the microtubules are attached to the centromere regions of the homologues. Lu -The synapsed tetrads are found aligned at the metaphase plate (the equatorial plane of the cell) instead of only replicated chromosomes. ANAPHASE 1-Chromosomes in each tetrad separate and migrate toward the opposite poles. -The sister chromatids (dyads) remain attached at their respective centromere regions. in TELOPHASE 1 -The dyads complete their migration to the poles. New nuclear membranes may form. -In most species, cytokinesis follows, producing two daughter cells. Each has a nucleus v containing only one set of chromosomes (haploid level) in a replicated form. ar (PMAT 2) PMAT 2 - Second Meiotic Division - the events in the second meiotic division are quite similar to mitotic division. M PROPHASE - The dyads contract. METAPHASE - The centromeres are directed to the equatorial plate and then divide. ANAPHASE - The sister chromatids (monads) move away from each other and migrate to the opposite poles of the spindle fiber. TELOPHASE - The monads are at the poles, forming two groups of chromosomes. A nuclear membrane forms around each set of chromosomes and cytokinesis follows. The chromosomes uncoil and extend CYTOKINESIS — the telophase stage of mitosis is accompanied by cytokinesis. -The two nuclei are compartmentalized into separate daughter cells and complete the mitotic cell division process. -In animal cells, cytokinesis occurs by the formation of a constriction in the middle of the cell until two daughter cells are formed. The constriction is often called cleavage, or cell furrow. GAMETOGENESIS -The production of sperm and eggs, takes place through the process of meiosis. -The production of sperm is called spermatogenesis and the production of eggs is called oogenesis. CHROMOSOMAL ABERRATION -This are changes in chromosome structure or number. na NONDISJUNCTION - is the failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes ANEUPLOIDY - a condition of having missing or extra chromosomes. 1. Turner Syndrome - does not have 2 sex chromosomes 2. Klinefelter Syndrome - extra y chromosome (xxy) 3. 4. Lu Metafemale (Triple X Syndrome) - tatlo ang x chromosome (xxx) Jacob’s Syndrome (Criminal Syndrome) - 3 ang sex chromosome/ extra y (xyy) AUTOSOMAL ABERRATION - aberration happens to 1st to 22nd pair of chromosome 1. Trisomy 21 (Down Syndrome) has extra chromosome in 21st pair 2. TRISOMY 18 (Edward’s Syndrome) is a chromosomal abnormality that often results in stillbirth or an early death of an infant. in 3. TRISOMY 13 (Patau Syndrome),is a chromosomal condition associated with severe intellectual disability and physical abnormalities. STRUCTURAL ABERRATION v Deletion Duplication ar Inversion Translocation M WEEK 5: LIPID FORMATION AND CELL MEMBRANE PROPERTIES - LIPIDS are amphipathic which means they have both hydrophilic and hydrophobic properties. LIPID BILAYER - are made of Lipids with bulkier and thicker polar tails (e.g. Glycolipids, Phospholipids, Cholesterol Lipids) - Phospholipids and glycolipids form the bilayer structure and not the micelles itself. LIPID FORMATION - When certain lipids are placed into water, they will spontaneously rearrange themselves to form structures called micelles. - Created by Fatty Acids, and it could be in Spherical, Ellipsoidal, Discoidal, and Cylindrical Structure. - Forces behind membrane or lipid formation are electric, and hydrogen bonds, and vander waals forces. na - HYDROPHOBIC EFFECT - the main driving force in membrane formation. - When amphipathic molecules are dispersed in water, their hydrophobic parts (i.e., hydrocarbon chains) aggregate and become segregated from the solvent. SONICATION - use of sound waves (carrying energy) to create artificial liposomes (vesicles). TRANSPORT MECHANISM: THE CELL MEMBRANE Lu LIPID BILAYERS - regulate the passage of solutes PLASMA MEMBRANE (CELL MEMBRANE) - transport mechanisms and separates the living cell from its surroundings. - SEMI-PERMEABLE BARRIER - lipids to perform those roles in FLUID MOSAIC MODEL -The modern understanding of the cellular or plasma membrane is referred to as the fluid mosaic model or fluid mosaics of lipids and proteins. - It is composed of a bilayer of phospholipids, with their hydrophobic, fatty acid tails in v contact with each other!! ang movement ay tila wave na umaalon alon shesh DAVSON- DANIELLI MODEL (1935) ar M - proteins from distinct layer (sandwich) FLUIDITY OF CELL MEMBRANE IS DUE TO: 1. Temperature, the configuration of the unsaturated fatty acid tails (some kinked or form a sharp twist by double bonds). 2. The presence of cholesterol embedded in the membrane; and, 3. The mosaic nature of the proteins and protein-carbohydrate combinations, which are not firmly fixed in place. Key takes in the fluidity of the cell membrane: Phospholipids in the plasma membrane can move within the bilayer. na Most of the lipids, and some proteins, drift laterally. Rarely does a molecule flip-flop transversely across the membrane As temperatures cool, membranes switch from a fluid state to a solid state. The temperature at which a membrane solidifies depends on the types of lipids. Lu Membranes rich in unsaturated fatty acids are more fluid than those rich in saturated fatty acids. Membranes must be fluid to work properly; they are usually about as fluid as in salad Oil. The steroid cholesterol has different effects on membrane fluidity at different temperatures. At warm temperatures (such as 37°C), cholesterol restrains movement of v Phospholipids. At cool temperatures, it maintains fluidity by preventing tight packing. ar THE STRUCTURAL COMPONENTS OF THE CELL MEMBRANE CELL MEMBRANE STRUCTURE -The landscape of the membrane is studded with proteins M (ang ibang protein ay nagseserve to transport materials in and out of the cell), some of which span the membrane. - In order to identify the cell to other cell, it needs to form complexes with the use of carbohydrates attached to proteins and lipids - the Cell Membrane is dynamic and constantly in flux. WEEK 6: MEMBRANE-CROSSING MECHANISM SELECTIVE PERMEABILITY - Plasma membranes lack symmetry: the membrane's exterior is not identical to its interior. - There is a significant difference between the arrangement of proteins and phospholipids and between the two leaflets that form a membrane. - Intrinsic Proteins (Integral) penetrate and bind tightly to the lipid bilayer (cholesterol is 4 to 10 nanometers in thickness) - Extrinsic Proteins (Peripheral) loosely bound to the hydrophilic (polar) surfaces which face the watery medium from both inside and outside of the cell KEY NOTES: Some proteins anchor to the membrane and to the cytoskeleton fibers may peripheral proteins sa exterior ng membrane na nagbbind ng extracellular matrix elements na Carbohydrates are found in Plasma Membrane’s exterior surface These carbohydrate complexes help the cell bind required substances in the extracellular fluid. This adds considerably to the plasma membrane's selective nature. SOLE REASON WHY IT IS SEMI-PERMEABLE: Because of its hydrophobic nature and not hydrophilic Lu v in DIFFUSION -from a region of high concentration to a region of low concentration. (lagi high to low baga dol) ar CONCENTRATION GRADIENT - is the difference in concentration between the two regions. M - Works well over short distances. -Once molecules enter the cell, the rate of diffusion slows. - Limits cell size & goal is to BALANCE!! OSMOSIS (an example of diffusion) - Diffusion of the solvent across a semipermeable membrane separating two solutions. (Diffusion of water) - Water molecules move from a region of high concentration to a region of low concentration. (high to low din) 1ST SITUATION: ISOTONIC - Water inside the cell equals the water outside the cell and equal amounts of water move in and out of the cell. 2ND SITUATION: HYPOTONIC - Water outside the cell is greater than that inside the cell, water moves into the cell, and may cause the cell to burst (lysis) 3RD SITUATION: HYPERTONIC - Water inside the cell is greater than outside. Water moves out of the cell, and may cause the cell to shrink (plasmolysis) na - HIGH TO LOW CONCENTRATION PRN Lu FACILITATED TRANSPORT/DIFFUSION (PASSIVE-MEDIATED TRANSPORT) - CARRIER PROTEINS - Transports non charged molecules with a specific shape. - CHANNEL PROTEINS - Tunnel shape that transports small charged molecules. in - DOES NOT REQUIRE water molecules for other molecules to transfer. v TRANSMEMBRANE, PROTEIN CHANNEL & TRANSPORTER ACTIVE TRANSPORT ar - LOW TO HIGH AMERNS - The process of moving substances against their concentration gradients. - Requires Energy. (which is ATP) M (E.G ACTIVE TRANSPORT PUMP:) 1. Kidney cells pump glucose and amino acids out of the urine and back into the blood. 2. Intestinal cells pump in nutrients from the gut. Root cells pump in nutrients from the soil. Gill cells in fish pump out sodium ions. - Sodium-potassium pump - 3 sodium ions inside the cell and 2 potassium ions outside the cell bind to the pump. - This allows the release of energy from ATP and causes the protein complex to change shape. - The change in shape allow the Na+ and K+ ions to move across and be released BULK TRANSPORT ENDOCYTOSIS - The cell membrane folds inward, traps and encloses a small amount of matter from the extracellular fluid. - transport is conducted by Phospholipid layers and molecules are transported by engulfing them. 3 TYPES OF ENDOCYTOSIS: 1. PINOCYTOSIS - The intake of a small droplet of extracellular fluid. This occurs in nearly all cell types. 2. PHAGOCYTOSIS - The intake of a large droplet of extracellular fluid. This occurs in na specialized cells. 3. RECEPTOR-ASSISTED ENDOCYTOSIS - The intake of specific molecules that attach to special proteins in the cell membrane. uniquely shaped ang protein woah (the one who engulfs) EXOCYTOSIS - The reverse of endocytosis: A vesicle from inside the cell moves to the cell SCIBULARY Lu membrane. The vesicle fuses to the membrane and the contents are secreted. - Removes waste products and secretes substances like hormones and enzymes. WEEK 7: ENZYMES CATALYST - a substance that speeds up a chemical reaction without being changed. ENZYME – a biological catalyst (usually a protein) in SUBSTRATE - the reactant molecule that an enzyme works on. ACTIVE SITE - the part of the enzyme where the substrate binds. ENZYME-SUBSTRATE COMPLEX - formed when the substrate molecule collides with the active site of its enzyme. v ENDOENZYMES (INTRACELLULAR) /EXOENZYMES (EXTRACELLULAR) ACTIVATION ENERGY - the minimum energy required to start a chemical reaction. TRANSITION STATE - the intermediate stage in a reaction in which the old bonds break ar and new bonds are formed. What do enzymes do? - it helps break large molecules into smaller pieces that are more easily absorbed by our body (e.g chocolate na binreak down into glucose tas icoconvert into ATP) M - WHAT ARE ENZYMES? Enzymes are protein macromolecules. They have a defined amino acid sequence and are typically 100- 500 amino acids long. They have a defined three-dimensional structure. Enzymes are catalysts. They act as a catalyst to a chemical or biochemical reaction, with a defined mechanism. - Enzymes are CATALYSTS (due to biochemical reactions tapos 106-1014 faster than uncatalysed reactions) & selective for a single substrate. - The rate speeds up by lowering the Activation Energy (Ea) - at optimal level only !!!!! Stereospecific because it only produces one product. - Enzymes are “mapili or maarte”, they only react to a specific substrate  - Enzymes are reusable !! Isang enzyme, maraming substrate Note: Enzymes are stereospecific meaning it only produces an single product after the reaction. Lock-Key Hypothesis - substrates are “fit” to enzymes active site. Induced fit model - the enzymes active site “adjust” to make way for substrates to bind (most accepted by the scientific community). Factors affecting enzymes na FACTORS AFFECTING ENZYME ACTIVITY - Lu Enzyme activity can be affected by a variety of factors, such as temperature, power of in Hydrogen (acidity & alkalinity), concentrations, and inhibitors. TEMPERATURE - raising the temperature will speed up a reaction and vice versa!! kaso kapag extreme na yung v temperature, mallose ang shape at kapag nawala ang basic shape ay hindi na pwede makapag undergo ng chemical reaction and magiging inactive ar - works best in optimum body temperature ng tao which is 37 degree Celcius and pag lumagpas ay hindi makakapagperform ng activity - kapag nagkakalagnat ang isang tao ay nagiging inactive ang enzymes kasi pinapataas ang temp para icombat ang mga bacterial infection. M - High temperature would mean the enzyme will denature (masisira) and loses its function. POWER OF HYDROGEN or POTENTIAL OF HYDROGEN (pH) - the enzymes illustrated are most active at about 5.0. & optimal is 7 !! pero depende paren - the higher ph, pwede rin magdeform ang enzyme - pag too acidic, madedenature ang protein and walang magaganap na reaction, same as alkalinity SUBSTRATE CONCENTRATION na - with increasing concentration of molecules, the rate of reaction increases until the enzyme molecules are filled. - any substrate concentration increase does not affect the rate of reaction Lu ENZYME CONCENTRATION - increasing enzyme concentration speeds up the reaction, as long as there is a substrate to bind to. - The higher the concentration of an enzyme the greater should be the initial reaction rate. in ENZYME INHIBITORS v (IRREVERSIBLE INHIBITORS) COMPETITIVE INHIBITOR - A molecule similar in ar structure to a substrate can bind to an enzyme‘s active site and compete with the substrate (naunahan ng competitive inhibitor yung substrate edi hindi makakagawa ng product) - panggulo lang etong si competitive inhibitor para iregulate ang enzymatic activity or homeostasis M - In order to combat competitive inhibitors, mas rumami dapat ang number of substrate and kaya lang naman nauuna si inhibit eme ay dahil sa affinity(or ability to bind) nito - For example sa case ng penicillin (antibiotic drug), a drug that inhibits (or stops) cell wall build of bacterias, the penicillin acts as an artificial substrate para unahan yung natural substrate ng bacterial enzyme. Therefore, if an artificial substrate binds first to bacterial enzymes responsible for cell wall creation, the bacteria will not create or regenerate its cell wall. This would expose them to outside environment and lead to their demise (death).  na NONCOMPETITIVE INHIBITORS - attach to the enzyme at an allosteric site, which is a site other than the active site distort the tertiary protein structure and alter the shape of the active site. Lu v in ar M