Science Reviewer - Plants and Humans - PDF

SCIENCE REVIEWER 1ST SEM [LAPID] PLANTS - Plants need Oxygen (O2 ) and Carbon dioxide (CO2) to GAS EXCHANGE AND TRANSPORT...

SCIENCE REVIEWER 1ST SEM [LAPID] PLANTS - Plants need Oxygen (O2 ) and Carbon dioxide (CO2) to GAS EXCHANGE AND TRANSPORT survive. - Our body uses oxygen to transform - Plants respire through stomata nutrients from food into energy. in leaves, lenticels, and root hairs. - The stomata (sing. stoma) are pores found on the leaves, stems, and other parts of the plant. GUARD CELLS - Guard cells are a pair of bean-shaped cells that surround the stoma. - The opening and closing of a stoma is controlled by guard - The oxygen is delivered to the body’s cells. cells and carbon dioxide is collected from the cells through the heart - Lenticels are openings on the outer surfaces of woody stems. Lungs - Gases diffuse into and out of - Terrestrial vertebrates have a pair of root hairs. lungs that allow the exchange of oxygen and carbon dioxide. - Oxygen dissolved in water enters the roots of the plant. - Animals that have lungs have a double-loop circulatory system. How are materials transported in plants? - Plants have vascular tissues that transport water, sugar, and dissolved minerals. - Xylem transports water and dissolved minerals from roots to stems and leaves. - 𝐶𝑂2 Gills - to survive. - Gills have blood vessels that help fishes obtain oxygen dissolved in water and release carbon dioxide. - Fish and animals that have gills have a single-loop circulatory system - Transpiration creates tension that pulls water up the xylem.  - Water moves against the force of gravity because of capillary action. ➔ COHESION: water molecules stick RESPIRATORY SYSTEM together - Inhalation ➔ ADHESION: water molecules stick to xylem walls - taking in oxygen - Our body’s cells need oxygen for cellular respiration - Exhalation - Eliminating in carbon dioxide - Carbon dioxide can be toxic to the body’s cells. - Phloem transports food (sugar dissolved in water) from photosynthetic cells to other parts of the plant for growth or storage. NOSE AND MOUTH - The nose is lined with cilia, which traps dust and dirt. - Air is warmed and humidified in the nasal cavity. PHARYNX - Receives air from the nose and mouth - Also receives food from the mouth - The epiglottis is a flap-like structure that prevents food from entering the larynx.  *The alveoli are lined with very small TONSILS blood vessels. In the alveoli, blood gets - found on the sides of the throat rid of carbon dioxide and picks up - trap and destroy pathogens that enter oxygen from the air we breathe in. This through the nose and mouth process is called gas exchange. LARYNX - Also called the voice box - Made up of two thick folds of tissue - The right lung has 3 lobes while the left called the vocal cords. lung has 2 lobes. TRACHEA DIAPHRAGM - Also called the windpipe - Large muscle found below the lungs - A tube that is held open by C-shaped - Creates air pressure changes in the chest cartilage rings cavity, resulting in breathing BRONCHI AND BRONCHIOLES - The bronchi branch into smaller and narrower tubes called bronchioles LUNGS - The major organs of the respiratory system - Has alveoli, the tiny air sacs where gas exchange occurs  AORTA CARDIOVASCULAR SYSTEM - first and largest artery - main artery that carries oxygen-rich blood from the heart to the rest of the body VEINS - bring blood back to the heart - thinner than arteries because there is less pressure - has one-way valves to prevent backflow TRANSPORTATION - oxygen, food, water, and other materials ELIMINATION - carbon dioxide and waste materials BLOOD VESSELS * Unlike arteries, veins are dependent on - Tubes that carry blood oneway valves to keep blood moving in an UPWARD motion. HEART - Pumps blood CAPILLARIES - smallest blood vessels BLOOD - deliver materials and take away wastes - transports materials from individual cells - only one-cell thick which allows gas exchange The thin walls of a capillary allows the exchange of materials. - The heart is a muscular pump that beats ARTERY - take blood away from the heart 70 – 75x / min. - have thick walls that withstand high pressure due to the heart’s pumping - the largest artery is the aorta - branch into arterioles ATRIA - Receiving chambers VENTRICLES - Pumping chambers LUNGS PULMONARY CIRCULATION - between the heart and the lungs RIGHT ATRIUM - receives oxygen-poor blood from the CORONARY CIRCULATION body - in the heart RIGHT VENTRICLE SYSTEMIC CIRCULATION - pumps oxygen-poor blood into the - between the heart and the rest of the lungs body LEFT ATRIUM WHAT ARE THE FUNCTIONS OF THE - receives oxygen-rich blood from the BLOOD? lungs - TRANSPORTATION LEFT VENTRICLE - oxygen, carbon dioxide, - pumps oxygen-rich blood into the rest nutrients, hormones, waste of the body - PROTECTION - fights infection and repairs damaged tissues *The valves - TEMP. REGULATION are thin flaps - helps maintain a steady body of tissue that temperature open and close to help the blood move.  WHITE BLOOD CELLS (WBC’S) 4 MAIN COMPONENTS OF THE BLOOD - also called leukocytes - PLASMA - protect the body from infections and - yellowish, liquid part of the illnesses by attacking pathogens blood - last only a few days and are constantly - carries blood cells, salts, replaced vitamins, sugars, minerals, proteins, and cellular wastes PLATELETS - where red blood cells, white - irregularly shaped pieces of cells blood cells and platelets are - plug wounds and stop bleeding suspended - responsible for blood clotting - RED BLOOD CELLS (RBCs) - also called erythrocytes - contain hemoglobin, an iron-rich molecule, which carries oxygen - has no nucleus and a has biconcave disk shape BLOODTYPES ANTIGEN - substance that can trigger the immune system ANTIBODY - clumping protein that attaches to antigens WHY DO RED BLOOD CELLS HAVE A BICONCAVE DISK SHAPE? - The Rhesus (Rh) factor is a type of protein that is found on the surface of a red blood cell.  An individual has 2 copies of each chromosome, one from each parent. An ALLELE is a variation of a gene. - alleles of the same gene are always found on the same location - alleles of the same gene may contain different information for a trait O is a universal donor but can only recieve from itself - The combination of alleles that an AB is a universal receiver but can only donate organism inherits makes up its to itself. genotype. - Phenotype refers to how the traits appear, or are expressed. DISORDERS OF THE RS AND CS - Common cold DOMINANT ALLELE - Bronchial asthma - always expressed - Pneumonia - example: E - Tuberculosis - COPD RECESSIVE ALLELE - COVID-19 - expressed only in the absence of a - Atherosclerosis dominant allele - Hypertension - example: e - Stroke - Heart attack - Hemophilia GENETICS - Traits are passed on from parents to offspring through genes. - Traits are characteristic features of an individual. - may be visible - may be hidden - inherited if inherent and not acquired GENES MENDELIAN - Genes are sections of DNA that contain - In the 1850s, Mendel performed information about a specific trait of that controlled breeding experiments with organism. pea plants.  - an inheritance pattern that follows the MULTIPLE ALLELES - A gene may have more than two laws of segregation and independent alleles. assortment in which a gene inherited - more than 3 phenotypes from either parent segregates into - may occur with codominance or gametes at an equal frequency. incomplete dominance NON-MENDELIAN INHERITANCE SEX RELATED TRAITS (SEX-LINKED & SEX-INFLUENCED) - When the allele for a trait is on an X or INCOMPLETE DOMINANCE Y chromosome, it is called a sex-linked - When an offspring’s phenotype is a trait. combination of its parents’ phenotypes, it is called incomplete dominance. X-Linked Trait - The gene for eye color is on the X chromosome. Red eye is dominant (W) while white eye is recessive (w). CODOMINANCE - When both alleles can be independently observed in a phenotype, it is called codominance. Y-LINKED TRAIT - If a trait is in the Y chromosome, all sons will express the trait. SEX INFLUENCED VS SEX LIMITED LATE DEVONIAN EXTINCTION - Sex-influenced traits are autosomal - 365 mya - 80% of all species on Earth became traits that are expressed differently in extinct different sexes. - may be due to global cooling and - Sex-limited traits are autosomal traits lowering of sea levels expressed in one sex only. - oxygen levels dropped POLYGENIC INHERITANCE PERMIAN-TRIASSIC EXTINCTION - occurs when multiple genes determine - 250 mya - The Great Dying the phenotype of a trait. - 96% of all species on Earth became extinct PEDIGREE - may be caused by the impact of an *A pedigree is a tool that shows genetic traits asteroid or by volcanic eruptions that were inherited by members of a family. - squares represent males TRIASSIC-JURASSIC EXTINCTION - circles represent females - 210 mya - 80% of land and marine species were lost EXTINCTION - may be caused by a massive lava flood - increase in carbon dioxide levels What does it mean when a species is acidified the oceans considered extinct? - A species is considered extinct when CRETACEOUS-TERTIARY EXTINCTION the entire population no longer exists. - 65 mya - also called Creteaceous-Paleogene Mass extinction occurs when many species - may have been triggered by an asteroid become extinct within a few million years or that created the Chicxulub Crater less. HOLOCENE EXTINCTION - Present - 12,000 years ago to present - also called the Anthropocene Extinction - driven by human activities ENDANGERED SPECIES - An endangered species is in danger of extinction while a threatened species is likely to be endangered. ORDOVICIAN-SOLURIAN - 440 mya - due to the dropping and rising of the sea levels, caused by the formation and melting of glaciers - 25% of marine families and 60% of the marine genera were lost PHOTOSYNTHESIS Photosynthesis is the process by which plants use light energy to produce food. REACTANTS: Carbon dioxide and water PRODUCTS: Glucose and oxygen The main pigments of photosynthesis are chlorophyll a and chlorophyll b. Where does most photosynthesis occur? - chlorophyll a: violet-blue and - Spongy mesophyll cells allow gases to orange-red light flow through. - Gases pass through the stomata. - chlorophyll b: blue and yellow light - Palisade mesophyll cells capture light energy. LIGHT-DEPENDENT REACTIONS 1. Excitation of Photosystems by Light Energy 2. Production of ATP via an Electron Transport Chain 3. Reduction of NADP+ and the Photolysis of Water Products: - ATP (adenosine triphosphate) Chloroplasts contain chlorophyll, which traps - NADPH (nicotinamide adenine dinucleotide phosphate) and stores light energy. - O2 (oxygen gas) Step 1: light excites chlorophyll electrons (in LIGHT-INDEPENDENT REACTIONS photosynthesis) and they become energized 1. Carbon Fixation 2. Reduction of G-3-P Photosystems are groups of photosynthetic 3. Regeneration of RuBP pigments (including chlorophyll) embedded Products: - C6H12O6 (glucose) within the thylakoid membrane - ADP (adenosine diphosphate) + Pi - NADP+ (nicotinamide adenine dinucleotide phosphate) CARBON FIXATION An enzyme, RuBP carboxylase (Rubisco), catalyses the attachment of a CO2 molecule to ribulose biphosphate (RuBP). When a photosystem absorbs light energy, delocalised electrons within the pigments This forms an unstable 6-carbon compound that become “excited.” They are transferred to carrier breaks down into two 3-carbon compounds. This molecules within the thylakoid membrane. 3-carbon compound is glycerate-3-phosphate (G3P). Step 2: excited electrons pass through electron transport chain, making ATP via chemiosmosis REDUCTION OF G-3-P Glycerate-3-phosphate (G3P) is converted into triose phosphate (TP) using NADPH and ATP. Reduction by NADPH transfers hydrogen atoms to the compound, while the hydrolysis of ATP provides energy. Step 3: electrons may reduce NADP+ (to form NADPH) and be replaced y photolysis of water LIGHT DEPENDENT REACTIONS REACTANTS: NADP+, ADP + Pi, H2O PRODUCTS:, NADPH, ATP, O2 AEROBIC RESPIRATION - Oxygen is present when this form of LIGHT INDEPENDENT REACTIONS respiration takes place. - Gases are exchanged in this form of respiration. - It can be found in the cytoplasm and the mitochondria. - Glucose breaks down into carbon dioxide and water. - All higher organisms such as mammals have this type of respiration. REACTANTS: CO2, NADPH, ATP PRODUCTS:NADP+, ADP + Pi, C6H12O6 ANAEROBIC RESPIRATION - Oxygen is absent when this form of CELLULAR RESPIRATION respiration takes place. - is a series of chemical reactions that - Gases are not exchanged in this form of respiration. convert energy in food molecules into a - It can be found only in the cytoplasm. usable form called ATP. - Glucose breaks down into ethyl alcohol, carbon dioxide and energy. - Lower organisms such as bacteria and yeast use this type. In other organisms, it occurs during heavy activities. - The matrix is the space surrounding the inner membrane that contains enzymes. - The cristae are folds in the inner membrane that increases the surface area to maximize energy production. GLYCOLYSIS Glucose is broken down in the cytoplasm. KREBS CYCLE / TCA CYCLE / CITRIC ACID CYCLE (matrix) Citric acid goes through a series of reactions that release energy. ELECTRON TRANSPORT CHAIN (cristae) Energy is used to produce ATP. Summary: 1 molecule of glucose (6 C) is broken down into 2 molecules of pyruvate (3 C). 1. Phosphorylation - A hexose sugar (typically glucose) is phosphorylated by two molecules of ATP (to form a hexose bisphosphate) - This phosphorylation makes the molecule less stable and more reactive, and also prevents diffusion out of the cell 2. Lysis - The hexose biphosphate (6C sugar) is split into two triose phosphates (3C sugars) 3. Oxidation - Hydrogen atoms are removed from each of the 3C sugars (via oxidation) to reduce NAD+ to NADH (+ H+) - Two molecules of NADH are produced in total (one from each 3C sugar) GLYCOLYSIS 4. ATP formation 1. Phosphorylation 2. Lysis - Some of the energy released from the 3. Oxidation sugar intermediates is used to directly 4. ATP formation synthesise ATP Products: - In total, 4 molecules of ATP are - 2 pyruvate generated during glycolysis by substrate - 2 NADH level phosphorylation (2 ATP per 3C - 4 ATP (net: 2 ATP) sugar)  - As electrons pass through the chain, they lose energy – which is used by the chain to pump protons (H+ ions) from the matrix - The accumulation of H+ ions within the intermembrane space creates an electrochemical gradient (or a proton motive force) Step Two: ATP Synthesis via Chemiosmosis - The proton motive force will cause H+ ions to move down their electrochemical gradient and diffuse back into matrix - This diffusion of protons is called chemiosmosis and is facilitated by the transmembrane enzyme ATP synthase - As the H+ ions move through ATP synthase they trigger the molecular rotation of the enzyme, synthesising ATP In the Krebs cycle, citric acid is formed Step Three: Reduction of Oxygen when acetyl CoA transfers its acetyl group to - In order for the electron transport chain oxaloacetate to make citric acid. Citric acid to continue functioning, the goes through a series of chemical reactions, de-energised electrons must be removed forming NADh, FADH2, CO2, and ATP. - Oxygen acts as the final electron acceptor, removing the de-energised ELECTRON TRANSPORT CHAIN electrons to prevent the chain from 1. Generating a Proton Motive Force becoming blocked 2. ATP Synthesis via Chemiosmosis - Oxygen also binds with free protons in 3. Reduction of Oxygen the matrix to form water – removing matrix protons maintains the hydrogen Step 1: Generating a Proton Motive gradient Force - In the absence of oxygen, hydrogen - The hydrogen carriers (NADH and carriers cannot transfer energised FADH2) are oxidised and release high electrons to the chain and ATP energy electrons and protons production is halted - The electrons are transferred to the electron transport chain, which consists of several transmembrane carrier proteins GLYCOLYSIS Reactants:1 C6H12O6 Products: 2 pyruvate, 2 ATP, 2 NADH LINK RXN Reactants: 2 pyruvate Products: 2 acetyl-CoA, 2 NADH, 2 CO2 KREBS CYCLE Reactants: 2 acetyl-CoA Products:, 2 ATP, 6 NADH, 2 FADH2, 4 CO2 ETC Reactants:10 NADH, 2 FADH2, 6 O2 Products: 32-34 ATP, 6 H2O FERMENTATION - is the process of breaking down glucose into simpler substances in the absence of oxygen. TOTAL ATP PRODUCED AEROBIC: 36-38 ANAEROBIC: 2