Grade 12 STEM General Biology 1 2nd Quarter Reviewer PDF

GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 BIOENERGETICS include some archaeans, especially those living in extreme branch of...

GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 BIOENERGETICS include some archaeans, especially those living in extreme branch of biology that studies environments: obtain energy by about how living things obtain and breaking down inorganic use energy substances to produce food without HETEROTROPHS sunlight cannot make their own food, instead they get their energy and PHOTOSYNTHESIS AND nutrients by eating other organisms CHEMOSYNTHESIS ARE THE ONLY PROCESSES THAT ALLOW ENERGY TO ENTER Exclusively Heterotrophic: OUR ECOSYSTEM. ANIMALS Carnivores-animals that eat REDOX REACTIONS animals (Oxidation-Reduction Reaction) always happen together Herbivores-animals that eat plants involve the transfer of electrons from one atom to another Omnivores-animals that eat both The atom that loses electrons is plants and animals called the oxidized substance, FUNGI the electron donor, or the don’t consume food by eating, reducing agent. instead they absorb nutrients from The atom that gains electrons is their environment called the reduced substance, eat decaying organic matter the electron acceptor, or the SAPROTROPHIC oxidizing agent. DEFINITION of OXIDATION: AUTOTROPHS Before: addition of oxygen to a substance organisms that can produce Modern: loss of electrons their own food using simple substances DEFINITION of REDUCTION: Before: removal of oxygen from a ❖ PHOTOSYNTHETIC substance use light Energy include plants, algae, and some Modern: gain of electrons bacteria: use light, carbon dioxide, and water to make food (glucose), oxygen, and water ATP ❖ CHEMOSYNTHETIC (Adenosine Triphosphate) use chemical Energy instant source of energy for cells PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 unstable These negatively charged high-energy molecule molecules push away nucleotide (monomer of nucleic from each other, making acids) the phosphoanhydride made up of a nitrogenous base, bond easy to break. a pentose, and three phosphate groups ATP-ADP Cycle ❖ ATP HYDROLYSIS ❖ HISTORY ATP + H20 → ADP + PO4⁻³ + ADENOSINE came from the words (Energy) Adenine - Nitrogenous base occurs when a cell needs energy ATP reacts with water that breaks Ribose - Pentose (5-carbon sugar) the phosphoanhydride bond TRIPHOSPHATE between the last two phosphate groups in ATP, turning it into ADP 1. Alpha Phosphate Group and releasing energy. only one that is attached to ribose ❖ PHOSPHORYLATION 2. Beta Phosphate Group connected to a phosphate ADP + PO4⁻³ + (Energy) → ATP + H2O by a high-energy Generally: the addition of PO4⁻³ to a phosphoanhydride bond molecule. which is represented by a tilde sign (~) ADP Phosphorylation 3. Gamma Phosphate Group energy is stored in the joined by a phosphoanhydride bond that is phosphoanhydride bond formed when a 3rd phosphate group with the beta phosphate is attached to ADP produces ATP and H2O ❖ PHOSPHOANHYDRIDE BOND ATP-ADP CYCLE SHOWS HOW high-energy bond, ATP IS GENERATED AND therefore, it can store TEMPORARILY STORES and carry more chemical ENERGY! energy COUPLED REACTIONS ❖ UNSTABLE? reactions that always occur ATP is unstable because together it has three phosphate groups that are all negatively charged. PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 PHOTOSYNTHESIS These wavelengths can reach Earth's surface and significantly impact cells. 6CO2 + 12H2O → C6H12O6 + 6O2 + 6H2O Infrared Light main product is Glucose contains too little energy to be of produces C6H12O6, O2, and H2O significant use to cells, as it is reactants: CO2 and H2O converted to heat which autotrophs series of Chemical Reactions cannot use for food production 2 stages of Photosynthesis: Light Ultraviolet Light Reactions and Calvin Cycle generally, it is Endergonic as it carries enough energy to damage stores energy DNA and do cells harm metabolic pathway: Anabolic, because it puts together simple III. Photosynthetic substances like carbon dioxide and Pigments water to produce complex Non-Photosynthetic Pigment substances like glucose ❖ ANTHOCYANINS 5 Requirements: main role is to protect plants from I. Reactants the damage created by UV Light Color: Purple; Blue Violet CO2 and H2O must be in the right Example: Pigments in amounts Bougainvillea Bracts and Onion CO2 have 6 moles while; H2O have 12 Bulb or Leaf Base moles The 2 Photosynthetic Pigments: II. Energy ❖ CHLOROPHYLLS Visible Light / White Light absorb visible light converts light energy into chemical region of the electromagnetic energy spectrum that can be detected by human eyes Reflected Light: GREEN only portion of the Absorbed Light: Some wavelengths electromagnetic spectrum that under RED and BLUE can be utilized by cells to power photosynthesis RED, BLUE, and GREEN In addition to visible light, there are Wavelengths used for wavelengths beyond the range of human photosynthesis vision, such as infrared and ultraviolet RED light. the best wavelength for photosynthesis PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 has more energy PHOTOSYSTEM Chlorophyll a contains around 300 chlorophyll a the primary, universal, important, molecules and main pigment of contains around 50 accessory photosynthesis pigments present in all photosynthetic ❖ REACTION CENTER organisms Pigment: Only 2 Chlorophyll a can both absorb light and convert molecules it to chemical energy ❖ LIGHT-HARVESTING Chlorophyll b COMPLEX can absorb light only Pigment: More Chlorophyll a and serves as an Accessory Pigment Accessory Pigments like Chlorophyll b and Carotenoids ❖ CAROTENOIDS IV. Enzymes Reflected Light: YELLOW, ORANGE, VIPs (Very Important RED Proteins) of the biological Absorbed Light: Regions under BLUE and world GREEN Very sensitive to pH Sensitive to temperature Example: Beta Carotene ENZYMES are BIOLOGICAL CATALYSTS Accessory Pigments ❖ RuBisCO absorb wavelengths of light that - a slow enzyme chlorophyll a cannot absorb - Has two substrates - Reason: Gene is slow to mutate Example: Chlorophyll b, Carotenoids ❖ ATP Synthase - has a channel that allows hydrogen ions in the thylakoid lumen to Location return to the stroma Eukaryotic Cell: Thylakoid Membrane of ❖ Ferredoxin-NADP reductase Chloroplast NOT ALL BIOLOGICAL Prokaryotic Cell: Cell Membrane CATALYSTS ARE PROTEINS, SOME OF THEM ARE NUCLEIC Pigments, along with proteins, are ACIDS! organized in groups called PHOTOSYTEMS. - If the temperature is too low, enzymes will not work and get deactivated. PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 - If the temperature is too high, - Light Harvesting Complex pigments are enzymes will not work and get called Antenna Pigments denatured. 3. Light Energy is transferred to the V. Optimum reaction center chlorophyll a Temperature Range Best Temperature 4. Electrons in the reaction center Results in maximum production chlorophyll a become excited Example: Corn: 22-25°C - These electrons are excited because they absorb additional energy Temperature Range (for photosynthesis) - When electrons absorb additional energy, - General temperature range is they move to a higher energy state diverse from 0 to ≈ 50°C 5. Two excited electrons are released by Example: Corn: 20-24°C the reaction center chlorophyll a LIGHT REACTIONS 6. Released electrons enter an ETC - occurs in thylakoid membrane (Electron Transport Chain) either the first - photo-part of photosynthesis ETC or the second ETC - Ligh-dependent 7. Electrons end up in their final electron - Stages: ATP Production and acceptor NADP Reduction - Main reactant: H2O - PSII = P700 (Electrons will go to the - Important Products: O2, ATP, chlorophyll a of photosystem I) NADPH - PSI = NADP (which is eventually Involve two types of photosystems: reduced to NADPH) (PSI) (PSII) 8. Photosystem must replace the electrons it lost Photosystem I and Photosystem II differ in the specific type of - PSII = water chlorophyll a molecule in their - PSI = PSII reaction center Chlorophyll a in the reaction center Flow of Light Reactions of Photosystem I is referred to as H2O > P680 > ETC 1 P700, while in Photosystem II, it is known as P680. - ETC 1 contains a series of proteins: Pheophytin, Quinones, Plastoquinones, General Events in Light Cytochrome Complex, and Plastocyanins Reaction P700 > ETC2 1. Photosystem has to be exposed to light 2. Absorb light energy PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 - ETC 2 contains nonheme iron proteins with his colleague, Andrew also called as Sulfur-iron proteins and Benson ferredoxin sometimes referred as the Calvin- Benson Cycle >NADP (reduced to NADPH) Has three stages: Carbon Fixation, (H2O is broken down in the process PGAL Synthesis, and the RuBP photolysis) regeneration Photolysis ❖ Carbon Fixation Water splits into O2 and H+ The process in which inorganic O2 will be used for cellular carbon from carbon dioxide is respiration (aerobic) incorporated into an organic H+ will go to the thylakoid lumen molecule, forming a more (note that there is also H+ in the stroma, stable and usable form of but the thylakoid lumen contains more H+; carbon for biological processes. though the thylakoid lumen contains more H+, these particles are transported actively An enzyme called RuBisCO from the stroma into the lumen) (ribulose bisphosphate carboxylase/oxygenase) catalyzes the energy released as the H+ return the reaction between CO2 and a to the stroma is used by the enzyme pentose with two phosphate group ATP Synthase to phosphorylate called RuBP (ribulose ADP bisphosphate). (This means that a phosphate group is added to ADP to produce ATP in the The reaction produces an unstable presence of light, that’s why it’s called hexose (6-carbon compound), photophosphorylation.) which immediately splits into two PGA (phosphoglyceric acid) Diffusion molecules. -the movement of particles from an area of higher concentration to an area of lower concentration The Calvin Cycle is also known as the C3 cycle because the first stable Calvin Cycle product of carbon fixation is PGA -synthesis part of photosynthesis (phosphoglyceric acid), a three- Occur in the stroma of the carbon compound (triose) attached chloroplast to a single phosphate group. Simple carbohydrates are produced using CO2, ATP, and NADPH ❖ PGAL Synthesis Discovered by the American During PGAL synthesis, the Biochemist Melvin Calvin along PGA (Phosphoglyceric acid or PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 Phosphoglycerate) molecules The six CO2 molecules in the formed during carbon fixation reactants of photosynthesis are converted into generate 12 PGAL molecules, ten phosphoglyceraldehyde of these are rearranged to form six (PGAL) or the glyceraldehyde- molecules of RuBP to sustain the 3-phosphate (G3P). cycle and the remaining two PGAL molecules are combined to form Its starts with the breakdown of the glucose. unstable hexose into two molecules of PGA. CELLULAR RESPIRATION Generally, it is exergonic as it Each PGA molecule is releases energy phosphorylated by ATP through the Metabolic Pathway: Catabolic, addition of a phosphate to PGA, because it involves breaking down forming BPGA a complex molecule such as (bisphosphoglyceric acid). glucose into simple substances like water and carbon dioxide The BPGA is reduced to PGAL (or Two types: Aerobic and Anaerobic G3P) using hydrogen ion from Performed by all organisms NADPH. This step results in the Eukaryotic Cells: happens in the conversion of two PGA molecules cytosol and mitochondrion into two molecules of PGAL. This Prokaryotic Cells: happens in the releases water as a by-product cytosol and cell membrane PGAL is a crucial intermediate in the ALL LIVING ORGANISMS Calvin cycle, as it can: PERFORM CELLULAR RESPIRATION! - Be used to regenerate ribulose bisphosphate (RuBP) to sustain the Reactants: cycle. Aerobic: C6H12O6, H2O, O2 - Serve as a building block for glucose, Anaerobic: C6H12O6 sucrose, and other carbohydrates. Products: ❖ RuBP regeneration Aerobic: CO2, H2O, ATP - The final stage of the Calvin Cycle Anaerobic: CO2, ATP, Organic Compound A portion of the PROCESS: phosphoglyceraldehyde (PGAL) molecules produced during PGAL Glucose is broken down by the cell to synthesis is recycled to regenerate release the energy stored in its RuBP. chemical bonds. PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 The energy released is not used splits into dihydroxyacetone directly; instead, it is temporarily phosphate and glyceraldehyde-3- stored in the high-energy bonds of ATP phosphate (PGAL). (adenosine triphosphate). ATP acts as the cell's immediate energy The dihydroxyacetone phosphate is currency, readily available to power quickly converted into PGAL, various energy-demanding resulting in two molecules of (endergonic) metabolic processes, such PGAL by the end of the energy as muscle contraction, active transport, investment stage. and biosynthesis. The Energy Harvest Stage Cellular respiration is essential for each of the two PGAL molecules producing ATP, with most organisms using receives a phosphate group from oxygen (aerobic) while some the cytosol’s phosphate pool, microorganisms rely on oxygen-free forming 1,3-diphosphoglyceric (anaerobic) processes in low-oxygen acid (1,3-bisphosphoglycerate). environments. This process reduces NAD ❖ GLYCOLYSIS (nicotinamide adenine dinucleotide) to NADH, which is Glycolysis, or "sugar-breaking," breaks used in aerobic respiration to down glucose (a six-carbon sugar) into generate more energy. two molecules of pyruvate (three-carbon One phosphate group from 1,3- compounds) in the cytosol. diphosphoglyceric acid is Anaerobic process, also known as transferred to ADP, producing ATP. the Embden-Meyerhof pathway The remaining phosphate group Occurs in two stages: the energy transforms 1,3-diphosphoglyceric investment stage, where ATP is acid into 3-phosphoglyceric acid, used, and the energy harvest which rearranges into 2- stage, where ATP and NADH are phosphoglyceric acid. produced. Dehydration of 2-phosphoglyceric acid forms phosphoenolpyruvate, The Energy Investment Stage whose phosphate group is begins when a phosphate group transferred to ADP, producing from ATP is added to glucose, another ATP molecule. forming glucose-6-phosphate. This Lastly, phosphoenolpyruvate is is rearranged into fructose-6- converted into pyruvic acid, phosphate, which then receives which ionizes to form pyruvate. another phosphate group from ATP The outcome for pyruvate and to form fructose-1,6-diphosphate. NADH depends on oxygen availability: aerobic respiration Energized by these two phosphate leads to further energy production groups, fructose-1,6-diphosphate PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 through the Krebs cycle, while while CO2 is released and may anaerobic conditions lead to diffuse out of the cell. This process fermentation to regenerate NADPH. occurs twice, as glycolysis produces two pyruvate molecules. Aerobic Respiration The high-energy thioester bond Aerobic respiration generates between CoA and the acetyl group ATP through the complete is also formed during this step. breakdown of glucose in the Some energy from glucose has been presence of oxygen. released during glycolysis and the Involves a series of chemical transition step, mainly as ATP and NADH. reactions: Glycolysis, the Krebs However, most of the energy is still stored cycle, and the respiratory chain in the acetyl-CoA molecules. To release Glycolysis always occurs in the cell's this energy, acetyl-CoA enters the Krebs cytosol, but the locations of the other two cycle, where it is further broken down. stages of aerobic respiration—the Krebs KREBS CYCLE cycle and the respiratory chain—depend on whether the cell is prokaryotic or Discovered by Hans Adolf Krebs eukaryotic. occurs in the mitochondrial matrix of eukaryotes and the cytosol of After glycolysis, pyruvate prokaryotes molecules do not immediately starts when acetyl-CoA combines enter the Krebs cycle. Instead, they with oxaloacetic acid (OAA) after undergo further oxidation in a short releasing its coenzyme sequence of reactions known as the transition step. PROCESS: Pyruvate Oxidation starts by adding a water molecule, which helps form citric acid. (This During the transition step, a pyruvate is why the cycle is also called the molecule undergoes oxidative citric acid cycle or the decarboxylation, where it loses carbon tricarboxylic acid or TCA cycle.) dioxide (CO2), hydrogen ions (H+), and electrons. citric acid is rearranged into Next is the removal of CO2 which isocitric acid (isocitrate). converts pyruvate into a two- carbon acetyl group, which then Isocitrate then loses a carbon as combines with coenzyme A (CoA) carbon dioxide in a reaction called to form acetyl-CoA, the activated oxidative decarboxylation, which compound that enters the Krebs also produces an energy-rich cycle. molecule called NADH. The electrons and H+ are picked up by NAD, reducing it to NADH, PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 This reaction converts isocitrate This means its carbon atoms have been into alpha-ketoglutaric acid released as carbon dioxide. Most of the (alpha-ketoglutarate). energy extracted from glucose at this stage is stored in molecules called The Krebs cycle continues with another NADH and FADH2, with a small step called oxidative decarboxylation, amount of ATP generated directly. where a carbon is removed from alpha- ketoglutaric acid. This step also adds a While the cell uses ATP directly to molecule of CoA, turning it into a four- perform work, NADH and FADH2 carbon compound called succinyl CoA are not directly usable for this purpose. These molecules instead Next, succinyl CoA is converted act as carriers of high-energy into succinic acid (succinate) by electrons. removing the coenzyme and adding The electrons carried by NADH a water molecule. and FADH2 are passed to the During this step, energy is released electron transport chain (ETC). to produce: ATP (in plant cells) As the electrons flow through the and GTP (in animal cells), which ETC, energy is released and used is a similar energy-carrying to pump protons (H+) across the molecule. membrane, creating a gradient. The rest of the cycle focuses on Through ATP synthase, the energy regenerating oxaloacetic acid initially carried by NADH and (OAA), ensuring the cycle can FADH2 is converted into a form the continue. cell can use: ATP The molecule GTP, which carries energy like ATP, transfers a phosphate group to ADP, forming ATP. succinic acid is oxidized into fumaric acid (fumarate), a process that produces FADH2 by capturing hydrogen ions (H+) and electrons. The Respiratory Chain Then, fumaric acid reacts with water to form malic acid (malate) This focuses on the electron transport Lastly, malic acid is oxidized back chain (ETC) and how it generates ATP during cellular respiration. into OAA, completing the cycle, while another NAD molecule is The ETC is made up of various reduced to NADH. This molecules, including regeneration of OAA ensures the flavoproteins, quinones, iron- Krebs cycle can continue repeating. sulfur proteins, and cytochromes. By the end of the Krebs cycle, glucose These molecules are organized into four complexes (I, II, III, IV), is completely oxidized. PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 each made of multiple subunits that As a rule: work together to transfer electrons. - For every NADH molecule, the Complex I contain FMN (flavin ETC generates approximately 3 ATP mononucleotide) and several molecules. nonheme iron proteins. It is the first complex to receive high- - For every FADH2 molecule, it energy electrons from NADH. generates approximately 2 ATP NADH donates its electrons to molecules. Complex I, while FADH2 transfers This reflects how the energy from NADH electrons to Complex II. and FADH2, captured during earlier stages These electrons are passed to of cellular respiration, is converted into ubiquinone (coenzyme Q). ATP, the cell's usable energy form. The electrons flow through the chain (Complexes III and IV) via a Types of Phosphorylation series of redox reactions, releasing energy at each step. - This describes the two mechanisms At the end of the chain, electrons by which ATP is produced during are accepted by O2, the terminal aerobic respiration: substrate-level (final) electron acceptor. Oxygen phosphorylation and oxidative combines with protons (H+) to phosphorylation. form two water molecules, Substrate-Level completing the process. Phosphorylation As electrons move through the complexes, energy is used to pump ATP is generated when a H+ (protons) from the phosphate group is directly mitochondrial matrix to the transferred from a substrate intermembrane space. molecule to ADP by an enzyme. This creates a proton gradient (a Happens in both glycolysis and the difference in H+ concentration) Krebs cycle. across the inner mitochondrial This process is enzyme-mediated membrane. and does not depend on a proton gradient or oxygen. The proton gradient drives the movement of H+ back into the Oxidative Phosphorylation matrix through ATP synthase. This movement of protons down ATP is synthesized by the enzyme their concentration gradient is ATP synthase, using the potential called chemiosmosis. energy stored in a proton gradient As H+ ions flow through ATP (also known as an electrochemical synthase, the enzyme uses the gradient). released energy to add a phosphate The proton gradient is created group to ADP, forming ATP. during the electron transport chain (ETC) as H+ ions are pumped into PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 the intermembrane space of the Actual Yield mitochondrion. In reality, additional energy is spent on: H+ ions then flow back into the mitochondrial matrix through ATP Transporting pyruvate and ADP synthase, a process called into the mitochondrial matrix. chemiosmosis. Other maintenance activities within ATP synthase uses the energy from the cell. this proton flow to attach a The actual ATP yield is around 30 phosphate group (from a phosphate ATP molecules per glucose. pool in the matrix) to ADP, Anaerobes forming ATP. This process is sometimes referred Some organisms, called to as chemiosmotic anaerobes, live in environments phosphorylation, as it relies on with little or no oxygen chemiosmosis to generate ATP. These organisms rely on anaerobic respiration or ATP yields from Aerobic fermentation to generate ATP. Respiration While these pathways do not - This highlights several important require oxygen, they yield points about the ATP accounting in significantly less ATP aerobic respiration, its efficiency, compared to aerobic respiration and a comparison with anaerobic Anaerobic Respiration pathways. This will highlight fermentation, a process While aerobic respiration produces energy, used by organisms to produce ATP in the certain steps consume ATP: absence of oxygen. Steps 1 and 3 of glycolysis: Fermentation begins with 2 ATP molecules are spent to glycolysis, which produces: phosphorylate glucose and convert it into fructose-1,6-bisphosphate, a - 2 ATP molecules (net gain). reactive intermediate. - 2 NADH molecules. Transporting NADH from the cytosol into the mitochondria - 2 pyruvate molecules. requires 1 ATP per NADH Unlike in aerobic respiration, molecule, adding to the energy NADH does not enter the ETC and cost. pyruvate does not undergo further Theoretical Yield oxidation Instead, NADH donates its - From glucose, aerobic respiration electrons to pyruvate (or a is often estimated to produce 36-38 derivative), regenerating NAD, ATP molecules under ideal conditions. PROJECT A-PEER By: ATT  GRADE 12 STEM A-PEER PDF REVIEWER 2nd QUARTER PERIODICAL S.Y. 2024-2025 GENERAL BIOLOGY 1 which is crucial for sustaining glycolysis. Types of Fermentation ❖ Ethanol Fermentation C6H12O6 → 2C2H6O + 2CO2 (+2 ATP) Process: For clearer explanation, kindly read 1. Pyruvate loses CO2, forming your 2nd Quarter Biology module. acetaldehyde. 2. Acetaldehyde is reduced by NADH, ROMANS 8:18 forming ethanol. Goodluck mga ka-tangkays!! Products: Ethanol, CO2, and 2 ATP. ❖ Lactic Acid Fermentation C6H12O6 → 2C3H6O3 (+2 ATP) Organisms - Bacteria (Lactobacillus, Streptococcus). - Human muscle cells (under low oxygen conditions). Process: - Pyruvate is directly reduced by NADH, forming lactic acid (or lactate). Products: Lactic acid and 2 ATP. Fermentation is an anaerobic process that enables ATP production when oxygen is unavailable. It regenerates NAD to sustain glycolysis, but produces much less ATP than aerobic respiration. PROJECT A-PEER By: ATT