Biochem (Lec) Finals Reviewer PDF

BIOCHEM (LEC) FINALS REVIEWER Precious ENZYMES Introduction to Enzymes Considered as the heart of biochemistry. Enzymes are protein in nature (with some...

BIOCHEM (LEC) FINALS REVIEWER Precious ENZYMES Introduction to Enzymes Considered as the heart of biochemistry. Enzymes are protein in nature (with some exceptions), and it catalyzes chemical reactions with rates ranging from 106 to 1012 times. Optimal temperature ranges from 0 - 100 C; 300 C Factors affecting reaction rates of enzymes. for deep sea bacteria, 20 - 40 C for most organisms. Temperature SIGNIFICANCE pH Enzyme inhibitors Enzymes aid in accelerating chemical reactions Allosteric Regulation within our bodies. For several processes, including Feedback inhibition liver function and digesting, enzymes are necessary. Cooperativity A particular enzyme's excess or deficiency might lead to health issues. Healthcare professionals can Effect of Increasing Temperature and Reaction Rates also use the enzymes in our blood to look for illnesses and injuries. Effect of Varying pH and Enzymatic Reaction Rates Effect of Competitive Inhibitors and Enzymatic Reaction Rates When an enzyme binds with the substrate, the substrate interacts with the enzyme causing it to FIGURE 7-5 Two-dimensional representation of Koshland’s induced fit model of the active site of a lyase. Binding of the substrate A—B change shape. This change in shape induces conformational changes in the enzyme that aligns catalytic residues which participate in catalysis and strains the bond facilitates the chemical reaction to between A and B, facilitating it cleavage. occur. This is called the induced fit. Effect of Competitive Inhibitors and Enzymatic Reaction Rates ACTIVE SITE o Active site can be further divided into: Effects of Allosteric Regulation BIOCHEM (LEC) FINALS REVIEWER Precious FEEDBACK INHIBITION Anabolic Reactions o The biological processes that create more complex molecules from simpler ones are catalyzed by anabolic enzymes. o Anabolic enzyme-catalyzed reactions need energy and ATP to function. o Asparagine synthetase, ATP synthase, phosphoglucomutase, DNA polymerase, and RNA polymerase are a few examples of anabolic enzymes. Catabolic Reactions COOPERATIVITY o Larger, more complicated molecules are broken down into smaller parts via biochemical reactions that are catalyzed by catabolic enzymes. o Catabolic enzymes catalyze reactions that release energy and produce ATP. Protease, lactase, cellulose, lipase, and sucrose Apoenzymes, Holoenzymes, Coenzymes and Cofactors are a few examples of catabolic enzymes. Many enzymes require an additional non-protein component to carry out its catalytic functions. Cofactors are non-protein components, that may be either one or more inorganic ions such as Fe2+, Mg2+, Mn2+ and Zn2+ or a complex organic molecule called coenzymes. Some enzymes require both coenzyme and one or more metal ions for their activity. A coenzyme or metal ion that is covalently bound to the enzyme protein is called prosthetic group. A complete, catalytically active enzyme together with its coenzyme and/ or metal ions is called holoenzyme. The protein part of such an enzyme is called apoenzyme or apoprotein. Apoenzymes are enzymes that is inactive due to the absence of a cofactor. Without the cofactor attached, Cofactor binding the protein is not active activates the protein. Role in Metabolic Pathways BIOCHEM (LEC) FINALS REVIEWER Precious BIOCHEMISTRY OF LIPIDS CLASSIFICATION AND FUNCTIONS What are Lipids? o A lipid is an organic compound found in living organisms that is insoluble (only sparingly soluble) in water but soluble in nonpolar organic solvents. o When a biochemical material (human, animal, or plant tissue) is homogenized in a blender and mixed with a nonpolar organic solvent, the substances that dissolve in the solvent are the lipids. o Lipids are formed by repeated units of fatty acids. o One class of Large biological molecules that do not form polymers. o The unifying feature of lipids is having little or no Types of Fatty Acids affinity for water. o Lipids are hydrophobic because they consist mostly of hydrocarbons, which Form non polar covalent bonds. o The most biologically important lipids are fats, phospholipids and steroids. GENERAL STRUCTURE OF A LIPID MOLECULE Saturated fatty acids Mono- unsaturated fatty acids CLASSIFICATION OF FATTY fatty Poly-unsaturated ACIDS acids ACCORDING TO CHAIN LENGTH SHORT CHAIN FATTY ACIDS GENERAL PROPERTIES OF LIPIDS a) 4-7 carbons Insoluble in polar substance b) liquid at room temperature Low melting point c) lipids in whole milk May be either liquids or amorphous solid MEDIUM CHAIN FATTY ACIDS Typically colorless, colorless, odorless, and tasteless High-energy organic molecules a) 8-12 carbons b) solidifies at lower temperature c) coconut oil BIOCHEM (LEC) FINALS REVIEWER Precious LONG CHAIN FATTY ACIDS a) more than 12 carbons b) solid at room temperature c) animal fat Cis double bond TWO MAIN TYPES OF CHOLESTEROL 1. Good cholesterol or high-density lipoprotein (HDL) Trans double bond o also known as ‘good’ cholesterol because it can help to protect you against coronary heart disease. 2. Bad cholesterol or low-density lipoprotein (LDL) o build-up of plaque (fatty deposits) in your arteries and increase your risk of coronary heart disease. HORMONE A biochemical substance, produces by a ductless gland, that has a messenger function. Hormones ser as a means of communication Fat – Solid Lipids between various tissues. Oil – Liquid Lipids A steroid hormone is a hormone that is a ROLE OF TRIGLYCERIDES IN THE HUMAN BODY cholesterol derivative. ✓ Provides energy ✓ Store energy in a form of fat ✓ Insulates and protect the body ✓ Transport fat – soluble vitamins GENERAL PROPERTIES OF TRILYCERIDES Melting point increases as the number of carbons increases in the hydrocarbon chain of the fatty acid. FIVE CLASSES OF HORMONES Triglycerides rich in UFA are liquid in room temperature and are called oils Triglycerides rich in SFA are either semi-solid or solid ate room temperature and are called fats. Wale was commercially used as source of oil. Such oil and fats include train oil from baleen whales, and melon oil from beluga whales. During the 16th-19th century, whale oil was used principally used as lamp fuel and for soap. STERIODS AND CHOLESTEROL o Steroids are lipids characterized by a carbon skeleton consisting of four fused rings 1. Progestins – active during pregnancy o Cholesterol, an important steroid, is a component in 2. Glucocorticoids – suppresses inflammation animal cell membranes 3. Mineralocorticoids – regulates ions in the body o Although cholesterol is essential in animal, high 4. Estrogens – female sex hormones that promotes levels in the blood may contribute to cardiovascular female sex characteristics. disease. 5. Androgens – promotes male sex characteristics BIOCHEM (LEC) FINALS REVIEWER Precious PHOSPHOLIPIDS CATABOLIC PATHWAY OR BREAKDOWN OF LIPIDS A major part of cell membrane. Digestion and absorption of lipids Amphipathic molecule From mouth to stomach – enzyme lingual lipase Has a hydrophobic part and a hydrophilic part. that emulsifies the lipid from food. In the stomach – gastric lipase starts to break down triglycerides into diglycerides and fatty acids. SPHINGOLIPIDS Going to the intestines to the bloodstream – Bile produced by the liver functions as an emulsifier. Consist of two nonpolar tails and a polar head Lipids become more surface area-rich through group emulsification, which enhances their accessibility Sphingosine, an amino acid, is the to the digestive enzymes. fundamental building block of a sphingolipid. Cell identification and signal transmission Used as biomarkers for diabetes, cancer, microbial infections, neurological disorders, and cardiovascular disease Includes ceramides, phytoceramides, glycosphingolipids, gangliosides, cerebrosides, and sulphated cerebrosides Structure of sphingosine and sphingolipids BIOLOGICAL WAX A long-chain fatty acid and a long chain alcohol connected via sigle ester bond. ANABOLIC PATHWAY – LIPOGENESIS Monoester Completely water-insoluble and solid at room temperature BIOCHEM (LEC) FINALS REVIEWER Precious Nucleic Acids: General Properties and Structure b. five-carbon (pentose) sugar - the sugar part of nucleic acids is either a d-ribose or d-2- deoxyribose. Depending Nucleic acid is a naturally occurring organic on the type of pentose sugar present, two kinds of macromolecule necessary for all organisms, nucleic acids can be formed--ribonucleic acids (RNAs) including viruses, to function. and deoxyribonucleic acids (DNAs). Both DNA and RNA The main function of nucleic acid is to store and have an aldopentose type of sugar in ring structure or express genetic information. furanose form. Nucleic acids are generally made of 3 units - phosphate, sugars, and nitrogenous bases. Nucleic acids, found inside the nucleus, hold the information that will instruct cells on what proteins to produce. These proteins serve as structural and regulatory components of a cell’s activity. Hence, all cellular activities are mediated by nucleic acids. There are two kinds of nucleic acids found in cells, Structure of sugar component in nucleotides ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Based on structure, nucleic acids are polymers called polynucleotides. Each Nucleotides having deoxyribose are called polynucleotide is made of a monomer, or several deoxyribonucleotides (found in DNA) while nucleotides units called nucleotide. having ribose are called ribonucleotides (found in RNA). There is a specific name and structure for every base that is attached to a sugar (nucleoside). The following are the diverse types of nucleoside base on attached nitrogenous base: uracil-containing = uridine (attached to ribose) / deoxyuridine (attached to deoxyribose) thymine-containing = ribothymidine (attached to Common to each nucleotide are the following ribose) / thymidine (attached to deoxyribose) materials: cytosine-containing = cytidine (attached to ribose - a. nitrogen-containing aromatic (cyclic) base – every Figure 2.129) / deoxycytidine (attached to deoxyribose) nucleotide sequence has 4 out 5 nitrogenous bases. A guanine-containing = guanosine (attached to ribose) / nitrogenous base is a heterocyclic ring that is either a deoxyguanosine (attached to deoxyribose) purine or pyrimidine. Pyrimidines are single cyclic bases that include- thymine (5-methyl-2,4-dioxipyrimidine), adenine-containing = adenosine (attached to ribose) / cytosine (2-oxo-4- aminopyrimidine), and uracil (2,4- deoxyadenosine (attached to deoxyribose) dioxoypyrimidine). Purine bases on the other hand are double ring structure like adenine (6-aminopurin) and guanine (2-amino-6-oxypurine). Both purine and pyrimidine are aromatic and absorb UV radiation (260 nm) making it a suitable candidate for spectrophotometric analysis. Structure of a nucleoside: Left- adenosine and right – thymidine c. phosphate molecule phosphate (PO4 -3) is a chemical compound made up of one phosphorus and four oxygen atoms. Phosphate, together with the aldopentose sugar, forms the sugar- phosphate backbone of nucleic acid. When phosphate forms ester bond with a nucleoside, the monomer nucleotide is produced. Nucleotide is the building block of a polynucleotide. A complete nucleotide – Guanylic acid or guanosine monophosphate BIOCHEM (LEC) FINALS REVIEWER Precious Polynucleotides Nucleotides can be connected to one another to form short sequences (oligonucleotides, with 2 to 10 nucleotide residues) or longer (polynucleotides, with more than 10 nucleotide residues). In these molecules, ribonucleotide (in RNA) or deoxyribonucleotide (in DNA) residues are joined to one another by 3′,5′-phosphodiester bonds, in which a phosphate residue is attached at the 3′ position of one nucleotide residue and the 5′ position of another. The sequence of nucleotide residues in an oligo- or polynucleotide is listed from the 5′-terminus to the Anti-parallel orientation of a DNA duplex, phosphodiester backbone, and base 3′-terminus (the OH groups on either end are not attached to nucleotide residues). Typically, the 5′ end is a phosphate monoester and the 3′ end a free OH group. Deoxyribonucleic (DNA) Every cell in a particular living thing contains the exact same DNA, and in plant and animal cells most of the DNA is found in the cell nucleus. Human DNA, which contains 3 billion paired deoxyribonucleotide residues, carries an estimated Ribonucleic Acid (RNA) 25,000 genes, stretches of DNA that carry the codes for protein production. Even this many genes account RNA is a single-stranded nucleic acid polymer like for only about 5% of the total DNA. The remaining DNA. However, RNA differs to DNA in terms of its “noncoding” DNA serves functions not yet bases. RNA has nucleotides A, C, G, and U. The understood in any detail. thymine is replaced by Uracil. RNA plays an important role in protein synthesis as it bears the code from DNA is a polymer that contains polynucleotides of DNA. adenine (A), cytosine (C), guanine (G), and thymine (T), attached to an alternating sugar-phosphate Compared to DNA, RNA is more chemically reactive. backbone. Base paring is always between a purine RNA reacts to the presence of alkali that cleaves the and a pyrimidine. This base pairing is determined by phosphodiester bond between the sugar and the allowed hydrogen bonds. phosphate. Although this chemical reaction does not o d. adenine + thymine = 2 hydrogen bonds play a significant role in cell’s activity since RNA is o e. guanine + cytosine = 3 hydrogen bonds almost perpetually synthesized and degraded inside the cell. The structure of DNA dates to 1953. It was James D. Watson and Francis H.C. Crick who proposed the Diversity of RNA three-dimensional structure for DNA based on X-ray crystallographic data. Watson and Crick won a Nobel Messenger RNA (mRNA) – delivers important code or Prize in 1962 for this remarkable work. One significant information from DNA to ribosomes. mRNA carries findings of their work are the discovery of two strands of necessary information coded by DNA that will determine DNA that forms the double helix structure. DNA is a the type of proteins the cell will produce. double helical structure. Several forms of DNA are found Ribosomal RNA (rRNA) – are the structural in nature. Normal DNA right-handed form is called the B- components of the ribosome. rRNAs play an important helix. A complete turn of a helix is around 10 base pairs. role in recognizing mRNA during protein synthesis. rRNA B-DNA has a wide major groove and a narrow minor production starts in the nucleolus, the organelle inside groove. the nucleus, where ribosomes are also produced. Theoretically, a single strand of DNA contains the Transfer RNA (tRNA) – composed of 70-80 nucleotides same A: T and G:C concentration with its complementary and carries amino acids into the ribosome during strand (Chargaff's rule). The bonding among polypeptide assembly. Each amino acid is carried by a complementary bases provides stability for the DNA specific tRNAs. structure. BIOCHEM (LEC) FINALS REVIEWER Precious TOPIC 2: Biochemical properties of DNA Deoxyribonucleic acids are large molecules with an average molecular mass pf 660g/mol per one base pair. With such structure and molecular weight, these macromolecules are also susceptible to modification or changes due to the following: Denaturation- it is already established that DNA is held together by several bonds like ester and hydrogen bonds. Increase temperature through heating caused the dissolution of hydrogen bonds between the bases. This heating causes melting or 4. Frameshift mutation – caused by either an insertion DNA denaturation. This results in the separation of or deletion in the DNA sequence causing a shift in the complementary strands. Hover, when cooled, the way the DNA sequence is read. two strands of DNA may reassociate and form the DNA double strand. Such a process is called renaturation or hybridization. The process of denaturing and hybridizing DNA has a particular use especially in the field DNA study such as mapping, fingerprinting, and forensic analysis. Ultraviolet absorption- DNA absorbs UV light at a wavelength of 260 nanometers. DNA quality can be monitored via UV absorption. Double stranded DNA absorbs UV radiation fairly compared to the single stranded version. Chemical modification- DNA can be chemically altered by intentionally exposing the structure to several enzymes like DNA methyltransferases that add methyl group to the structure. Oxidation, use KEY POINTS of radiation, exposure to carcinogens like ethidium bromide and colchicine. These studies are Nucleic acids are the primary biomolecules important for understanding nucleic acid reaction present in all cells and viruses that play a key role to several materials. This leads in the determination in protein synthesis, storage, and transfer of of carcinogenic, mutagenic, and genotoxic material. genetic heritage (heredity). Nucleotides are the monomers of nucleic acids. The collection of nucleotides is referred to as TOPIC 3: Mutation polynucleotide, the nucleic acid. Nucleotides, whether DNA or RNA, are made of Mutation is a change in the DNA sequence. This sugar, phosphate, and nitrogenous base. change can be a result of copying mistakes during DNA Nucleic acids can be denatured by chemicals and synthesis, exposure to mutagens or mutating chemicals, heat and can absorb radiation. or even radiation. The result of mutation can cause DNA and RNA can mutate causing change in their change in the RNA sequence that later changes the structure resulting to change in the translated amino acid sequence. A classic example of this change or protein. mutation is the Sickle cell disease where the sixth codon of the beta globin chain – GAA is altered to GTA. Such singular codon changes result in structural atrophy in red blood cells. Thus, a normal RBC becomes sickle in shape, limiting the oxygen carrying capacity of the said cell. Nucleotide substitution may lead to the following cases: 1. Silent mutation – change in DNA sequence in a gene that results to no effect on the resulting amino acid sequence. 2. Missense mutation – alteration of DNA sequence resulting to a different amino acid that later changes the integrity of protein. 3. Nonsense mutation - a single nucleotide substitution causing abrupt stop in translation process. BIOCHEM (LEC) FINALS REVIEWER Precious From DNA to Proteins: Central Dogma of Molecular Biology Flow of genetic information from DNA to RNA to protein. An individual DNA is translated into messenger RNA (mRNA). Then, the RNA is translated into protein by the sequential addition of amino acids that are coupled to tRNA molecules. Flow of genetic information from DNA to RNA to protein Order of activities 1. Unwinding proteins 2. Single-strand binding proteins 3. Primase makes RNA primer 4. DNA polymerase makes DNA 5. RNAse H removes RNA primer 6. DNA polymerase fills in gaps 7. DNA ligase joins gaps Why is DNA Replication important? The important idea is that an exact duplication of the DNA message is required, so that each new cell in the body has the same set of genetic instructions as the cells that preceded it. This also ensures that every new generation of individuals has the same genetic information as his/her parents. Important notes about transcription RNA molecule is synthesized from a segment of DNA that includes a gene are like DNA nucleotides but have a (slightly) The “Central Dogma” in Prokaryotes and different backbone. Eukaryotes T is replaced with U (U = Uracil) DNA Replication BIOCHEM (LEC) FINALS REVIEWER Precious Translating the protein The start codon marks the site at which translation into protein sequence begins, and the stop codon marks the site at which translation ends Start codon AUG while stop codons are UAA, UAG and UGA Translation Translation is the synthesis of protein from RNA that takes place on ribosome The mRNA sequence is read three bases at a time from its 5’ end toward its 3’ end, and one amino acid is added to the growing chain from its respective transfer RNA (tRNA), until the complete protein chain is assembled. Translation stops when the ribosome encounters a termination codon (UAG, UAA, or UGA. BIOCHEM (LEC) FINALS REVIEWER Precious Bioenergetics Even though all chemical processes are a subfield of biochemistry that examines the technically reversible, the conditions in a cell availability and energy of biological systems. frequently make it more efficient from a the study of energy transformations in living thermodynamic perspective for flux to move in organisms. one direction. examines how cells, tissues, and organs interact with A chain of protein complexes and other each other to convert energy from food into the molecules known as an electron transport chain energy that powers all of life. (ETC) couples’ protons (H+ ions) across a study the interactions between energy and other membrane with the transfer of electrons from biological systems, such as hormones and enzymes. electron donors to electron acceptors via redox the area of biochemistry concerned with how cells reactions (both reduction and oxidation occur convert energy, frequently through the synthesis, storage, or use of adenosine triphosphate. simultaneously) The transport of electrons from NADH and Mitochondria FADH2 to the ETC requires two mobile electron the powerhouse of the cell, responsible to produce carriers and four massive multi-subunit enzyme energy through the process of oxidative complexes. The membrane contains many of the phosphorylation. enzymes in the electron transport pathway. In this process, electrons from various substrates are passed through the respiratory chain of the inner mitochondrial membrane, releasing energy that is used to form ATP. The function of the mitochondria is not only to produce energy, but also to regulate many cellular processes including apoptosis, cell signaling, and calcium homeostasis. Metabolism It describes the assortment of chemical reactions that sustain an organism. There are three main goals of metabolism: ✓ to eliminate metabolic waste ✓ break down food into its component proteins, Biological Oxidation-Reduction Reactions lipids, and some carbohydrates, ✓ transform the energy in food into energy that Oxidative phosphorylation, also known as the can be used by cells. electron transport chain, is a process in Catabolic and anabolic metabolic reactions are the mitochondria that involves the release of energy breakdown of substances (e.g., cellular respiration from photosynthesis and cellular respiration converts glucose to pyruvate) and the production of The process involves the electron transport substances (e.g., proteins, carbs, lipids, and nucleic chain (ETC) and chemiosmosis, where proteins acids). Energy is normally used during anabolism and released during catabolism. affixed to the inner mitochondrial membrane and organic molecules allow electrons to pass Roles in metabolism through and release energy They are essential to produce energy for the cell The energy released is used to create ATP, while through the process of cellular respiration. light energy is converted into chemical energy During cellular respiration, electrons are passed during photosynthesis. through the electron transport chain, and the energy released is used to produce ATP. The mitochondria play a crucial role in energy conversion and are responsible for harnessing the energy released during oxidation and transferring it into a form that the cell can use. Principle Compounds of the Common Metabolic Pathway Biological reactions that make up each metabolic pathway are linked together by their intermediates; for example, the products of one reaction serve as the substrate for the next, and so on. It's common knowledge that metabolic pathways move in a single direction. BIOCHEM (LEC) FINALS REVIEWER Precious The Chemiosmotic Pump in ATP Production Cellular Respiration Electron donors like NADH and FADH contribute Three Major Stages of Cellular Respiration electrons to the electron transport chain during Glycolysis is the breakdown of glucose to chemiosmosis, modifying proteins' conformation to pyruvate where small amounts of ATP are pump H+ through a selectively permeable cell produced. This process occurs in the cytoplasm membrane, creating an electrochemical gradient due of the cell. to their positive charge. Citric acid cycle or tricarboxylic acid cycle or In oxidative phosphorylation, the hydrogen ion Krebs cycle degrades pyruvate to carbon dioxide, gradient formed by the electron transport chain is water, ATP and reducing power in the form of used by ATP synthase to form ATP NADH, H+. This stage happens in the matrix of the mitochondria. Oxidative phosphorylation which includes electron transport chain and chemiosmosis generates high amounts of ATP. This stage occurs in the inner membrane of the mitochondria. Glycolysis Hydrogen Ion Diffusion in Membrane Hydrogen ions diffuse spontaneously over membranes due to electrochemical gradient. Ion channels are essential for ion diffusion in nonpolar areas of phospholipid membranes. ATP synthase is the only membrane protein allowing hydrogen ions to pass through the inner mitochondrial membrane. Hydrogen ion diffusion turns ATP synthase into a small generator, adding phosphate to ADP and creating ATP. Chemiosmosis, a process in mitochondria, generates 90% of ATP during Aerobic Glucose Catabolism, while anoxidative phosphorylation captures sunlight energy for photosynthesis lighting reactions. The reactions convert hydrogen atoms into ATP, reducing oxygen into ion ions and attracting hydrogen ions from the surrounding medium, forming water. The glucose molecule contained these atoms Glycolysis Pyruvate produced by glycolysis are oxidized in the mitochondria, freeing high energy electron & a carbon in the form of CO2. KEY POINTS When oxygen is not present, anaerobic During chemiosmosis, the free energy from the respiration or fermentation occurs. series of reactions that make up the electron transport chain is used to pump hydrogen ions across Glycolysis (Fermentation) the membrane, establishing an electrochemical During fermentation, organic compounds break gradient. down. Hydrogen ions in the matrix space can only pass Hydrogen from NADH attaches to pyruvate, through the inner mitochondrial membrane through forming lactic acid or ethyl alcohol (ethanol). a membrane protein called ATP synthase. Pyruvate loses a molecule of CO2 as it accepts an As protons move through ATP synthase, ADP is electron from NADH. turned into ATP. This generates NAD+, w/c enables glycolysis to The production of ATP using the process of continue. chemiosmosis in mitochondria is called oxidative Microorganisms uses fermentation to produce phosphorylation. small amounts of ATP in the absence of O2 BIOCHEM (LEC) FINALS REVIEWER Precious Electron Transport Chain Named after Hans Krebs, the biochemist whose work in the 1930s revealed how these reactions work. Glycolysis (Fermentation) The chemiosmotic pump, or ATP synthase, is a Without oxygen, fermentation can produce membrane protein that generates ATP molecules by lactic acid or ethanol and carbon dioxide gas. moving hydrogen ions (protons) across a membrane This happens in your muscles during workouts Chemiosmosis involves the pumping of protons through when there is not enough oxygen. special channels in the membranes of mitochondria from the inner to the outer compartment. The pumping establishes a proton (H+ ) gradient. Energy Yield from Electron and Proton Transport Krebs Cycle Adenosine triphosphate (ATP) is produced because Named after Hans Krebs, the biochemist whose work of the movement or momentum that occurs as in the 1930s revealed how these reactions work. electrons move along a chain. The Krebs Cycle, also known as the citric acid cycle, For many biological functions, such as muscle is a central metabolic pathway occurring in the contraction and cell division, ATP serves as the mitochondria of cells primary energy source. It plays a key role in cellular respiration, breaking Adenosine triphosphate (ATP) is an organic chemical down acetyl-CoA derived from carbohydrates, fats, that provides energy for cell and proteins. The cycle produces energy in the form of ATP and captures high-energy electrons in carrier molecules. These electrons later contribute to the electron transport chain, further generating ATP. The Krebs Cycle completes the oxidation of glucose, releasing carbon dioxide as a byproduct and facilitating the production of cellular energy. BIOCHEM (LEC) FINALS REVIEWER Precious CELLULAR RESPIRATION Enzymes manage energy transition from ATP hydrolysis to chemical bond synthesis. Energy Yield from Cellular Respiration ATP performs chemical, mechanical, and Glycolysis 2 ATP transport tasks. Citric Acid Cycle 2 ATP ATP can propel chemical reactions, move Electron Transport Chain and chemiosmosis objects, or force molecules across membranes. 26-28 ATP Top ATP consumers include proteinbuilding enzymes like tRNA synthetase. 2-3 ATP per NADH in Electron Transport Muscle Contraction and Motor Proteins Chain ATP powers muscle contraction and cargo 1-2 ATP per FADH2 in Electron Transport movement in cells. Chain Motor proteins, when coupled to ATP, take on a single form. Hydrolysis of ATP to ADP alters protein structure, producing mechanical force. Motor proteins move along cell cytoskeleton, depleting one ATP molecule. Myosin, a motor protein, splits numerous ATP molecules to produce significant force. Human Body's Energy Consumption ATP-powered "pumps" in brain cells are the largest energy consumers. These pumps create electrochemical gradients for neuron interaction. Pump proteins transport molecules across cell membranes against concentration gradients. Various pumps move specific types of ions, like sodium, potassium, or protons. Some pumps move other tiny molecules. Conversion of Chemical Energy to Other Forms of Energy ATP Energy in Chemical Processes ATP powers chemical processes like DNA replication and protein construction.