Human Physiology Exam Module 1: Chapter 1-5

Where does glycolysis take place? cytosol The study of the functions of organisms Define physiology Homeostasis Maintenance of relatively constant conditions within the body's internal environment Homeostatic control mechanism The CONTROL CENTER receives and process information from receptors about changes in a particular variable, and compares it to the set point. If the variable is outside the set point, the control center initiates a response to bring the variable back to its normal range. (C) Negative feedback (normal) A type of feedback commonly employed in homeostatic regulatory systems in which the response of a system goes in a direction opposite to the change that set it in motion. Set point the normal or desired value of the regulated variable in a homeostatic regulatory system Intergrading center group of cells, usually in the CENTRAL NERVOUS SYSTEM (CNS) or an endocrine gland, that use sensory information to determine a response and communicate commands to effectors Effectors cells, tissues, or organs that respond to neural o chemical signals; in homeostatic regulatory systems, cells, tissues, or organs that respond to output signals of the intergrading center and bring about the final response; also called the effector organs Positive Feedback (push further away) type of feedback in which the response of a system goes in the same direction as the change that set it in motion Four major cells types Neurons, Muscle cells, epithelial cells, and connective tissue cells Total body water (TBW) total volume of water in all compartments; it includes both intracellular fluid (ICF) and extracellular fluid (ECF) ICF and ECF ICF is located inside the cells; ECF is located outside the cell; ECF in the blood is called plasma; fluid that found outside the blood is called interstitial fluid (ISF) separated by the epithelial tissue that lines blood vessels; accounts for one-third of the total body water Homeostatic regulatory mechanism Sensors, integrating center, and effectors Describe some basic cellular functions Providing structural support, facilitating growth and reproduction, enabling energy production, and allowing for the transport of substances. Epithelial continuous, sheetlike layers of cells found in the skin and linings of hollow organs; specialized to regulate exchange; Muscle fibers muscle cells Neurons specialized cells in the nervous system that communicate via electrical and chemical signals; also known as nerve cells Connective tissue cells tissue whose primary function is to provide physical support for other structures, to anchor them in place, or to link them together Internal enviornment fluid that surrounds the cells inside the body, including the fluid in the bloodstream that surrounds blood cells; aka extracellular fluid ICF Fluid located inside the cells, accounts for two-thirds of total body water; extracellular fluid that is present outside the blood, and bathes most of the cells of the body Which of the following best illustrates the concept of positive feedback? C The hormone aldosterone stimulates the reabsorption of sodium ions from the lumen of a kidney tubule. Based on your knowledge of the body's cell types, you can surmise that this hormone acts on C hormones are secreted C which cell type is specialized for contraction and generation of force? A) Muscle the body's internal environment is synonymous with extracellular fluid maintenance of consistent conditions in the internal environment is known as ______________ homeostasis what accounts for the total body water content? ICF and ECF what cells in the body respond to glucagon by breaking down glycogen and releasing glucose? liver cells when blood glucose levels are low, the pancreas releases glucagon which eventually causes blood glucose levels to increase ( True/False) A) True The integration center for homeostatic control of blood glucose in the B in negative feedback, what are the effectors? Glands and Muscles connective tissue consists of cells dispersed in a noncellular material called the ___ Matrix connective tissue consists of cells dispersed in a noncellular material called the _____________ Connective tissue cells What is intrinsic control? Intrinsic control refers to local responses initiated within the tissue or organ itself. Do intrinsic controls involve the nervous or endocrine systems? No, intrinsic controls do not involve the nervous or endocrine systems. What detects changes in the environment or local conditions in intrinsic control? Specialized cells or tissues within the specific tissue or organ detect changes. What is extrinsic control? Coordinated responses involving the nervous and endocrine systems for a broader response to changes in the body. What systems are involved in extrinsic control? The nervous and endocrine systems. What detects changes in internal or external conditions in extrinsic control? Specialized nerve endings or endocrine glands. Which part of the brain is primarily involved in extrinsic control? The hypothalamus. Eukaryotic cells plasma membrane- outermost boundary of the cell, composed of phospholipid embedded proteins and acts as a selective barrier controlling molecules into and out the cell. Nucleus- DNA and directs synthesis of proteins and ribosomes serves as the control center and regulating growth and reproduction Mitochondria- Generates most of the cell's energy in the form of ATP through cellular respiration, especially aerobic respiration Rough ER- Studded with ribosomes and membrane proteins Smooth ER- lipid synthesis and lacks ribosomes Golgi Apparatus- Receives proteins and lipids from the ER, modifies, sorts, and packages them into vesicles for transport to their final destinations within or outside the cell. Lysosomes (animal cells) - Membrane-bound organelles containing hydrolytic enzymes and Break down waste materials, cellular debris, and foreign substances through processes like autophagy and phagocytosis. Peroxisomes- Small, single membrane-bound organelles. and Carry out oxidation reactions, breaking down fatty acids and amino acids, and detoxifying harmful substances, including the breakdown of hydrogen peroxide Cytoskeleton- protein filaments extending throughout the cytoplasm and Provides structural support, maintains cell shape, facilitates cell movement, and helps in the transport of organelles Vacuoles- Membrane-bound sacs with various functions. and Storage compartments for water, nutrients, and waste Summarize the stages of cellular respiration 1. Glycolysis - break down of glucose into pyruvic acid. 2 ATP/cytoplasm/anaerobic 2. Kreb's cycle - break down of pyruvic acid. 2 ATP/mitochondria/aerobic 3. ETC - creates 38 ATP/mitochondria/aerobic What is passive transport? Movement of molecules down a concentration gradient without the need for energy. What is active transport? Movement of molecules up a concentration gradient that requires an input of energy, often using ATP. What is simple diffusion? The process by which small, nonpolar molecules cross the membrane without the need for transport proteins. What is facilitated diffusion? The process where larger or polar molecules and ions require membrane proteins to assist in crossing the membrane, moving down their concentration gradient. What is osmosis? The specific passive transport of water across a semipermeable membrane, driven by differences in solute concentration. Describe the roles of a source cell, messenger, target cell, receptor, and signal transduction in cell-to-cell communication. a source cell releases a messenger molecule, which travels to a target cell. The target cell possesses a receptor protein that binds to the messenger, initiating signal transduction, a process that transmits the signal to the cell's interior. Describe the function of the receptor, control center, effector, and feedback ina homeostatic control mechanism The receptor detects the changes in its environment and sends a signal to the control center which takes that date and relays it back to effector to get back to the setpoint. Biomolecules -molecules synthesized by living things -contain carbon 4 basic types of biomolecules carbohydrates, lipids, proteins, nucleotides carbohydrates are made of carbon, hydrogen, oxygen in a ratio of 1:2:1 Monosaccharides Simple sugar composed of a single unit glucose Most common monosaccharide, C6H12O6. provides important source of cellular energy Disaccharides carbohydrate consisting of two monosaccharides covalently bonded together Glycogen a glucose polymer found in animal cell functions as an energy store Starch polysaccharide found in plants Cellulose Polysaccharide of glucose found in plants that humans are unable to digest or absorb Hydrolysis use of water to split another molecule Lipids Biomolecules that contain primarily carbon and hydrogen atoms linked together by nonpolar covalent bonds Amphipathic a molecule having both polar and nonpolar regions, as in phospholipid molecules Glycerol Three-carbon alcohol that functions as the "backbone" of a triglyceride or phospholipid Fatty acids Long hydrocarbon chains w/ a carboxyl group (--COOH) at one end Triglyceride A lipid consisting of three fatty acids linked to a glycerol backbone; commonly called fat Phospholipid Amphipathic lipid molecule consisting of a glycerol backbone to which two fatty acids and phosphate containing chemical group are attached Eicosanoids Modified fatty acids (all derived from arachidonic acid) that function in intercellular comm Steroids Lipids derived from cholesterol consisting of three six carbon rings and one five-carbon ring; many function as hormones Proteins Polymers containing amino acids joined together by peptide bonds; usually refers to chains containing more than 50 amino acids Polypeptides Polymer containing amino acids joined together by peptide bonds peptides short chains of amino acids (usually less than 50) Nucleotides A biomolecule containing one or more phosphate groups, a five-carbon carbohydrate, and nitrogenous base; involved in energy exchange and in the storage and transmission of genetic info in cells Nucleic acids polymers of nucleotides that function in the storage and expression of genetic info Deoxyribonucleic acid (DNA) a biomolecule consis of two strands of nucleotides coiled together as a double helix; Found in the nucleus and stores genetic info Ribonucleic acid (RNA) polynucleotide molecules found in a cell nucleus and cytoplasm of genetic info Includes messenger RNA, transfer RNA and ribosomal RNA Cell Structure and Function plasma membrane barrier separating a cell from the extracellular fluid consis of of phospholipids, proteins and cholesterol Nucleus -contains cell DNA -in the Central nervous system (CNS) Cytoplasm everything inside the cell except the nucleus Cytosol Cytoplasm minus membrane-bounded organelles Organelles -cells consists of biomolecules -carry out specific functions of the cell Auaporins water channels located in the plasma membrane of most cells integral membrane proteins embedded within the lipid bilayer Transmembrane proteins -integral membrane proteins that span the lipid bilayer -exposed to cytosol and interstitial fluid Peripheral membrane proteins loosely bound to the lipid bilayer with integral membrane proteins or phospholipids Endoplasmic reticulum -elaborate network of membranes inside cells that encloses a single interior compartment -has endoplasmic and smooth endoplasmic reticulum Ribosomes -has RNA and proteins -functions in protein synthesis -found in the cytosol and Rough ER Golgi Apparatus organelle consists of membrane-bound flattened sacs called CISTERNAE -synthesized in the ER and prepare them for transport Lysosomes spherical membrane-bounded organelles -breakdown intracellular material or foreign matter has enters the cell Peroxisomes Molecules such as amino acids, fatty acids, and toxic foreign matter Metabolism Sum of all the chemical reactions that take place in the body Catabolic (catastrophic = Blown up) breakdown of large molecules into smaller molecules generally releases energy Anabolic (ANA-b-building) Synthesis of large molecules from smaller molecules generally requiring an input of energy Phosphorylation either added to a molecule or removed from it Oxidation-reduction a type of reaction where electrons are removed from an atom or molecule and then accepted by another atom or molecule Condensation Involves the joining together of two or more smaller molecules to form a larger one dephosphorylation removing a phosphate group from a molecule typically a protein or DNA Adenosine triphosphate (ATP) -primary direct energy source for cell -synthesized ADP and inorganic phosphate (Pi) -Its structure consists of a nitrogenous base (adenine), a ribose sugar, and three phosphate groups -it provides energy for anabolism NAD+ -Structurally, NAD++ is essentially a pyridine that is composed of two nucleosides linked by pyrophosphate to form its stable structure. -The NAD+ and NADH are crucial for a variety of important cellular processes, including DNA repair, epigenetically controlled gene expression, oxidative phosphorylation and ATP synthesis, intracellular calcium signaling, and immunological functions. FAD -FAD's structure consists of a riboflavin moiety linked to an ADP molecule -FAD is derived from riboflavin, a vitamin B2 -FAD exists in two forms: the oxidized form (FAD) and the reduced form (FADH2). FAD in metabolism -FAD participates in the electron transport chain, transferring electrons during the oxidation of food molecules. -xidation-reduction reactions -FAD is involved in the citric acid cycle, where it accepts electrons from the oxidation of certain molecules. -The energy released during the transfer of electrons by FAD contributes to the production of ATP in the electron transport chain. Glycolysis (splitting of sugar) -the first stage of glucose oxidation, occurring in the cytosol, in which -each glucose molecule (6 carbon) is broken down into 2 pyruvate that turns into (pyruvic acid) containing 3 carbons The Krebs cycle -a cyclical metabolic pathway occurring in the mitochondrial matrix, in which acetyl coenzyme A is a primary reactant and carbon dioxide and reduced coenzymes are produced; also called the citric acid cycle or TCA cycle The linking step The step in which pyruvate is converted into acetyl CoA by the reduction of NAD+ to NADH+H+ to produce CO2 What is the initial substrate for the Krebs cycle? Acetyl CoA How many ATP molecules are produced during glycolysis? 2 How many ATP molecules are produced during the linking step? 0 How many ATP molecules are produced during the Krebs cycle? 2 what are the two steps of oxidative phosphorylation? 1. electron transport chain 2. chemiosmotic coupling how many ATP are made during oxidative phosphorylation? 28 ATP Synthase the enzyme that synthesizes ATP during oxidative phosphorylation; located in the inner mitochondrial membrane electron transport chain a series of electron acceptors and other protein in the inner mitochondrial membrane; involved in the synthesis of ATP by oxidative phosphorylation chemiosmotic coupling the entire process that couples electron transport to ATP synthesis; the utilization of energy released during electron transport to transport hydrogen ions across the inner mitochondrial membrane up their concentration gradient glycogen a glucose polymer found in animal cells; functions as an energy store glucogenesis process during which new glucose molecules can be synthesized from noncarbohydrate precursors by the liver what 3 substrates are made during glycogenesis? 1. amino acids 2. glycerol 3. lactate where does glycogenesis mainly occur? liver How many NADH+ are reduced to NADH during glycolysis? 2 During which step of glucose oxidation is there no O2 consumed or CO2 produced? glycolysis How many molecules of CO2 are made during the linking step? 2 how many NADH are used during the Krebs cycle? 6 how many FADH are used during the Krebs cycle? 2 What is created when the cell performs glucose catabolism in low oxygen conditions? lactate how many ATP are produced in low oxygen conditions (synthesis of lactate)? 2 where is glycogen stored? muscle, liver and kidneys glycogenesis building up of glycogen by glucose-6-phosphate glycogenolysis breaking down of glycogen to glucose-6-phosphate glucose-6-phosphatase enzyme in the liver and kidneys that allows glucose to leave the cell proteolysis the conversion of proteins to amino acids is called lipolysis the process of breaking down triglycerides for energy FAD, NAH, CoA 3 coenzymes particularly important in energy metabolism Phosphatase an enzyme that catalyzes dephosphorization what are the 3 stages of glucose oxidation? 1. glycolysis 2. the Krebs cycle 3. oxidative phosphorylation what is the first step in the ETC? high energy electrons (NAHD+ and FADH2) are released from glycolysis what is the second step in the ETC? thoe electrons come in and react with hydrogens; moving down a concentration gradient (OXIDATION) What is the third step in the ETC? water is formed by reacting with oxygen (REDUCTION) what is the fourth step in the ETC? ATP is generated how much ATP do carbohydrates produce? 34-38 what is important about the role of glycolysis in the ETC? it produces more H+ ions which allows for more production of ATP Desmosomes Cell junctions resembling small 'spot welds' that hold adjacent cells together, with interlocking fibers on the outer surface and anchored internally by intermediate filaments of the cytoskeleton. Gap junctions Membrane channels of adjacent plasma membranes connecting to form gaps or 'tunnels' that join the cytoplasm of two cells, allowing certain molecules and electrical impulses to pass directly from one cell to another. Tight junctions Cell junctions occurring in cells joined near their apical surfaces by 'collars' of tightly fused membrane, preventing molecules from easily permeating between cells, commonly found in the lining of the intestines and other parts of the body. Describe the basic structure and function of an extracellular matrix. The extracellular matrix consists of cross-linked molecules and proteins that surround all cells and tissues, providing them with support and structure. The role of the extracellular matrix is to help in communication between cells, it facilitates the attachment of cells to each other, enables the movement of cells and their growth. Explain the role of chemical, electrical, and electrochemical driving forces in the passive transport of substances across a membrane. These driving forces are all used to move molecules across the cell. Chemical driving forces move molecules based on the concentration of molecules, electrical and electrochemical driving forces move molecules/ions based on the concentration of ions/molecules and charges Differentiate between passive and active transport in relation to a substance's gradient. Passive transport does not require energy but active transport requires energy Identify the 3 general factors that influence passive transportation rates. - Magnitude of Driving Force - Membrane surface area - Permeability Identify the 2 general factors that influence active transport. - Concentration of Pumps/ channels - The rate of individual pumps/channels Identify factors which affect membrane permeability during simple diffusion. - Solubility- Membranes are lipids therefore more likely to dissolve hydrophobic molecules (non-polar) - Temperature- affects the fluidity of the hydrophobic bilayer - Membrane thickness - thicker membranes are generally harder to permeate. - Size and Shape of molecule- larger and irregularly sized molecules move through the membrane slower. Compare the movement across the membrane by carriers and channels. Both carriers and channels are specific to which molecules they let through but carriers go through conformational change whilst channels transport using pores. Channels transport faster than carriers. Distinguish between secondary and primary active transport. Primary active transport directly uses ATP hydrolysis to move molecules against their gradient -while secondary active transport utilizes the electrochemical gradient created by primary active transport to power the movement of other molecules. Describe how differences in solute concentration between the ICF and ECF alter solution tonicity and influence osmosis. ECF is outside the cell is the buffer between the cell and the enviornment outside the boy. Everything that enters or leaves most cells passes through the ECF Describe the direction and purpose of endocytosis (receptor-mediated, pinocytosis, and phagocytosis) and exocytosis. -Transport into and out of the cell can be accomplished through vesicles. It is typical for large water-soluble molecules, liquid content, or even complete cells such as bacteria. -Endocytosis is when vesicles move into a cell. Exocytosis is when vesicles are expelled from a cell. Vesicle formation in both cases requires ATP consumption. -These types of transports are specific processes, not random. An example is a receptor-mediated endocytosis. It occurs when specific substances such as cholesterol or growth factors bind to receptors on the cell membrane. Binding triggers the invagination of that part of the membrane, so a vesicle forms, and the substance enters the cell. When solid particles enter the cell by endocytosis, it is called phagocytosis. The immune system cells ingest harmful substances and bacteria this way. Pinocytosis refers to the endocytosis of small vesicles filled with liquid. Examples of exocytosis are the secretion of mucus, digestive enzymes, hormones, and neurotransmitters. Distinguish between passive transport and active transport and recognize examples. Passive transport-net flux is down the electrochemical gradient-glucose transport is example of facilitated diffusion -Active transport-net flux is up the electrochemical gradient Define endocytosis and exocytosis and explain the primary difference between these and other mechanisms of cellular transport. endocytosis-molecules in the ECF are brought into the cell via the formation of an endosome -phagocytosis-pinocytosis (non-specific) -receptor-mediated endocytosis (specific)exocytosis-molecules are packaged into secretory vesicles inside the cell and released into the ECF -also helps to add cell membrane material that is removed during endocytosis Compare the three major functional classes of chemical messengers (paracrines, neurotransmitters, and hormones) with respect to the cell that releases them and the ways the messengers reach their targets. paracrines-reach target cells via simple diffusion -target cells are very close byautocrines-act on the cell that secreted them neurotransmitters-synaptic signaling -neurons are the secretory cell-synapse-specific hormones-released from glands mostly except for neurohormones -all cells are exposed but only cells with receptors are affected Describe the basic structure and function of each chemical class of messenger (amines, catecholamines, peptides, steroids, and eicosanoids) with regard to mechanisms of synthesis, release, transport, and signal transduction. Amines-lipophobic -receptors in plasma membrane -functional classification: paracrines, neurotransmitters, hormones catecholamines include dopamine, epinephrine, norepinephrine Peptides-lipophobic -receptors in plasma membrane -functional classification: paracrines, neurotransmitters, hormones Steroids-lipophilic -receptors in cytosol (few in the plasma membrane) -functional classification: hormones Eicosanoids-lipophilic -receptors in cytosol -functional classification: paracrines amino acids-lipophobic -receptors in plasma membrane -functional classification: neurotransmitters Compare and contrast the signal transduction mechanisms for lipophilic and hydrophilic messengers. lipophobic messengers-secreted by exocytosis travels through the blood after it dissolves lipophilic messengers -secreted by diffusion 99% bound to carrier proteins in the plasma 1% are left as free hormones so that it can bind to receptor at target cell Channel-linked receptors -membrane bound receptor -will only cause a channel to open when ligand binds -aka ligand-gated channel -acts as a receptor and a channel -fast receptor but effects are brief -also can interact with intracellular proteins for varied responses calcium ligand gated channel -messenger binds -calcium enters acts as second messenger -sends to calmodulin -activates protein kinase -creates protein -response in cell enzyme-linked receptors -membrane bound receptor -two in one-chemical messenger binds to receptor and activates enzyme -most common is tyrosine kinase -kinase phosphorylates protein on tyrosine residue left with ADP -then causes response in cell -fast receptor, brief effects G-protein-linked receptors -can cause channel to open or close -slow gated ligand channels regulated by g protein -receptor associated with g protein made of multiple subunits that can slide along bilayer (alpha, beta, gamma, and GDP) -protein activated by exchange of GDP for GTP -only alpha subunit dissociates from other subunits, slide along bilayer, attach to channel and tell it to open or close or attach to enzyme and stimulate or inhibit it G protein regulated enzymes and second messengers is produces -result in the production or activation of a second messenger include -cAMP -cGMP -DAG -IP3 -Calcium Compare and contrast communication mediated through the nervous and endocrine systems. -The nervous system typically impacts ion channels causing a fast but short response -uses electrical and chemical transmission -endocrine system send signals through the blood -impacts protein synthesis or acts on g protein linked receptors -slower effect but longer lasting Amino acid messengers -glutamate, aspartate, glycine (used in protein synthesis)GABA -hydrophilic -receptors on the plasma membrane -synthesized within neurons and not from food -synthesized in the cytosol -packaged into vesicles and stored there until exocytosed amine messengers -all possess an amine group includes:catecholamines -dopamine-primarily acts as neurotransmitter -norepinephrine-primarily acts as neurotransmitter -epinephrine-primarily acts as a hormone serotonin-neurotransmitter histamine-paracrine thyroid hormones-only amine that is lipophobic-receptor on the cell nucleus