...The functions of protein are linked to their shape Proteins are polymers of amino acids joined by strong peptide bonds. The combination of any of the twenty amino acids in any length and sequence allows an almost infinite number of possible structures and functions. The sequence of amino acids in the polypeptide chain is termed the primary structure. The primary structure is unique to a given protein. The primary structure can fold regularly to form either an α-helix or β-pleated sheet. The secondary structure is held together by hydrogen bonds between adjacent peptide bonds. The primary structure can further fold in an irregular but not random manner to form an overall three dimensional shape that more specifically determines the biological functions of the individual protein. This 3D structure is held together by bonds formed between the R-groups of amino acids. For movement, animals use muscle contraction. Muscle fibres are composed of two protein filaments, myosin which is a thick filament and actin which is thinner. Actomyosin cross-bridges can form between the two which move relative to one another on hydrolysis of ATP drawing actin into myosin. This sliding filament theory shows how a sarcomere contracts. This contraction is used in a variety of applications including constriction or dilation of blood vessel to modify blood flow through tissues, pupil diameter to control light entry into eyes or the generation of a force at a joint to move a hand away from a hot...
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...1. collagen Major structural protein (285 kDa) of extracellular matrix. An unusual protein in amino acid composition (very rich in glycine (30%), proline, hydroxyproline, lysine and hydroxylysine; no tyrosine or tryptophan), structure (a triple-helical arrangement of 95-kDa polypeptides giving a tropocollagen molecule, dimensions 300×0.5 nm), and resistance to peptidases. Most types are fibril-forming with a characteristic quarter-stagger overlap between molecules producing an excellent tension-resisting fibrillar structure. Type IV, characteristic of basal lamina, does not form fibrils. Many different types of collagen are now recognized. Some are glycosylated (glucose–galactose dimer on the hydroxylysine), and nearly all types can be cross-linked through lysine side chains. 2. elastin Glycoprotein (70 kDa) randomly coiled and crosslinked to form elastic fibres that are found in connective tissue. Like collagen, the amino acid composition is unusual with 30% of residues being glycine and with a high proline content. Cross-linking depends upon formation of desmosine from four lysine side groups. The mechanical properties of elastin are poorer in old animals. 3. keratins Group of highly insoluble fibrous proteins (of high _-helical content) which are found as constituents of the outer layer of vertebrate skin and of skin-related structures such as hair, wool, hoof and horn, claws, beaks and feathers. Extracellular keratins are derived from cytokeratins, a large and diverse...
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...PROTEIN FUNCTION-MYOGLOBIN AND HEMOGLOBIN 208.5.3-01-05 Hemoglobin Model Comparison to Oxygenated and Deoxygenated Hemoglobin The Bohr Effect * The Bohr effect is the relationship between hemoglobin and pH’s ability to bind oxygen. I will explain this in more detail. We begin our journey in the lungs. Our lungs have the most amount of oxygen in the body. This is a good thing because our hemoglobin is strongly attracted to and has a high affinity to oxygen. The oxygen gets heavily bound to the hemoglobin and this helps to deliver the oxygen to rest of the body. The Bohr effect allows the steady release of this bound up oxygen throughout the body while the blood is delivered to the other parts of the body such as the fingers and toes. You see our pH in the lungs is around 7.4. As the blood moves through our body our pH is changed to around 7.2 because the blood picks up carbon dioxide. Carbon dioxide is produced by our cells in the citric acid cycle and each round of the citric acid cycle causes our carbon dioxide to increase. Each cell performs this citric acid cycle, which causes a lot of carbon dioxide to build up. Our blood picks the carbon dioxide up to be able to bring it back to the lungs to be blown out of the body, but as the blood is picking up carbon dioxide it is also leaving the oxygen it needs from the blood. You see the Boher effect allows this to happen. Bohr Effect Graph Hemoglobin vs. Myoglobin Sickle Cell Anemia (amino acid) Diagram Sickle Cell Anemia...
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...Chapter 11 * Principles of Membrane Transport * Given enough time, nearly all molecules will diffuse across a membrane * Smaller, hydrophobic/non polar molecules diffuse rapidly * Larger molecules, and charged ions move much slower * So mechanisms are needed * 2 Main types of Membrane Transport Proteins * Transporters * Bind to a specific solute and undergo shape change to move solute through membrane * Channels * Much more weakly interact with molecules * Create pores that allow specific molecules to pass through * Allows much more rapid transport * Passive/Facilitated Transport * Used by all channels and some transporters * This uses no energy and moves molecules “downhill,” with their electrochemical gradient * Active Transport * Used by transporters, here usually called pumps * Requires energy, ATP * Move molecules against the electrochemical gradient * Transporters and Passive Transport * Glucose Transport * Passive transport * Cooperative transport coupled with the transport of Na+ * Binds 2 Na+ and 1 glucose * The binding of either ligand, glucose or Na+, increases binding of the other. The concentration of Na+ outside the cell is greater, so the net movement transports more of both ligands into the cell. * Transporters and...
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... Learning outcomes: 1. Explain how a cell can make a variety of large molecules from a small set of molecules 2. Define monosaccharides, disaccharides, and polysaccharides and explain their functions 3. Define lipids, phospholipids, and steroids and explain their functions 4. Describe the chemical structure of proteins and their importance to cells 5. Describe the chemical structure of nucleic acids and how they relate to inheritance Copyright © 2012 Pearson Education, Inc. Rearrange these in the correct order: INTRODUCTION TO ORGANIC COMPOUNDS © 2012 Pearson Education, Inc. 3.1 Life’s molecular diversity is based on the properties of carbon Carbon-based molecules are called organic compounds. Methane (CH4) is one of the simplest organic compounds. – Four covalent bonds link four hydrogen atoms to the carbon atom. – Each of the four lines in the formula for methane represents a pair of shared electrons. © 2012 Pearson Education, Inc. Three representatives of methane (CH4) Structural formula Ball-and-stick model Space-filling model The four single bonds of carbon point to the corners of a tetrahedron. Different bond angles and shapes occur when carbon atoms form double bonds. Hence, a molecule’s shape determines its function 3.1 Life’s molecular diversity is based on the properties of carbon Compound composed of only carbon and hydrogen are called hydrocarbons. Carbon, with attached hydrogens (aka carbon...
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...Globular proteins or spheroproteins are spherical "globe-like" proteins and are one of the common protein types (the others being fibrous, disordered and membrane proteins). Globular proteins are somewhat water-soluble (forming colloids in water), unlike the fibrous or membrane proteins. There are multiple fold classes of globular proteins, since there are many different architectures that can fold into a roughly spherical shape. Examples: * Insulin – regulatory hormone for controlling glucose metabolism * Myoglobin – involved in oxygen storage in muscles * Hemoglobin – involved in oxygen transport in blood * Transferrin – involved in iron transport in blood * Immunoglobulins – involved in immune system responses Fibrous proteins is a protein with an elongated shape. Fibrous proteins provide structural support for cells and tissues. There are special types of helices present in two fibrous proteins α-keratin and collagen. These proteins form long fibers that serve a structural role in the human body. Fibrous proteins are distinguished from globular proteins by their filamentous, elongated form. Also, fibrous proteins have low solubility in water compared with high solubility in water of globular proteins. Most of them play structural roles in animal cells and tissues, holding things together. Fibrous proteins have amino acid sequences that favour a particular kind of secondary structure which, in turn, confer particular mechanical properties on the proteins...
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...CELLS AND ORGANELLES Cell Membrane: consist of a lipid bilayer. Hydrophobic tails are located in the interior. Transmembrane protiens are anchored to the core of the bilayer and can be removed only by detergents that disrupt the bilayer. Peripheral membrane proteins are attatched to the cell surface electrostatically and are easily removed by altering the pH. Eucaryotic cells with outer- and intra- cellular membranes ~ half the cell’s total volume -separate intracellular organelles Nucleus- double membrane-bound organelle containing chromatin. Contains the genetic blueprint for every protein in the body. Nuclear Envelope- separates and mediates transport between the nucleus and the cytoplasm and is supported by intermediate filament proteins, the lamins. Nucleolus- dense non membrane bound structure. rRNA synthesis and ribosome assembly. Ribosome-consists of 2 subunits of ribosomal RNA. Protein synthesis- formation of peptide bonds between amino acids to make polypeptide chains using messenger RNA as a template. Endoplasmic reticulum- (rER) Protein synthesis (sER)is involved in steroid synthesis and detoxification. Golgi apparatus- determines vesicle fate. Finaly assembly and glycosylation of proteins. Mitochondria – double membrane bound energy production mainly in the form of ATP Lysosomes- high acidity, killing of pathogenic organisms, and degradation of waste products. Endosomes- Peroxisomes – production of hydrogen peroxide for killing pathogens...
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...network for your 100,000,000 cells -Communication System: NERVOUS * Functions: 1. Collects Information 2. Processes Information 3. Initiates Response * Communication Method: -Nerve signal travels along the neuron then the neurotransmitter is released into the synaptic cleft * Target Cells: 1. Other Neurons 2. Muscle Cells 3. Gland Cells * Response Time: RAPID * Duration of Response: SHORT (terminates with removal of stimulus) -Communication System: ENDOCRINE (Chemical Communication System) * Functions: 1. Maintaining homeostasis 2. Regulating development, growth, and metabolism 3. Controlling Reproductive Activites * Communication Method: -Produces and releases hormones-regulatory chemicals (proteins or lipids) secreted into the blood stream and affects target cells. * Target Cells: -A variety of cells with a specific receptor for a hormone that initiates or inhibits selective cell activities. * Response Time: LONGER * Duration of Response: LONGER LASTING (mins to days and weeks) 17.2 -Endocrine Cells: 1. Derived from epithelium with connective tissue framework 2. Have extensive blood supply to facilitate rapid uptake of hormones 3. Two Locations: -Single Organ: pineal, thyroid, pituitary, parathyroid, and adrenal glands -Cells in small clusters in organs with another primary function: stomach, liver, pancreas -Endocrine glands: scattered throughout the...
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...Biochemistry Task 2 October 17, 2015 (Yatherajam, 2015) (Yatherajam, 2015) Organic Compounds. Retrieved October 16, 2015, from http://legacy.owensboro.kctcs.edu/gcaplan/anat/Notes/API Notes D organic chem.htm Polypeptides (n.d.) Retrieved October 16, 2015, from http://www.sparknotes.com/testprep/books/sat2/biology/chapter5section5.rhtml Pepsin Enzyme: Structure, Function, and Important Facts. (2014, September 25). Retrieved October 16, 2015, from http://www.buzzle.com/articles/pepsin-enzyme-structure-function-and-important-facts.html There are four forces, both bonds and interactions, which help stabilize or hold together a tertiary structure. These four forces include hydrophobic interactions, hydrogen bonds, ionic bonds, and disulfide bonds. Hydrophobic interactions are the weakest of the four forces and they occur between nonpolar amino acids. According to Borges (2014) these hydrophobic interactions occur in amino acids such as leucine and phenylalanine. The amino acids involved in hydrophobic interactions are amino acids which are not capable of hydrogen bonding. The next force is hydrogen bonding, which occurs between polar or charged amino acids like tyrosine and aspartate, according to Borges (2014). At the oxygen level the amino acids share their hydrogen atom with one another, one hydrogen atom becomes the donor and the other the recipient. The hydrogen bond is stronger that...
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...Cystatins are small human proteins that mainly function as protease inhibitors and are found throughout the body. Proteases are enzymes that begin to break down proteins. They can function intracellularly and extracellularly in order to inhibit their target cysteine enzymes (Ochieng, 2010). This allows the proteins to maintain the balance of protease inhibitors versus the proteins and regulate any damaging activity by the proteases. By sustaining the balance between proteases and cystatins found in the body, immunomodulatory functions, which are any factors that cause change within the normal immune system, not related to protease inhibition, can be regulated. This is very important because impairment in inflammatory responses can cause...
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...Biology Units 3 &4 Notes -Chapter 1- The Chemical Nature of Cells | |Protein |Carbohydrates |Fats |Nucleic acid | |Monomer |Amino acids |Monosaccharaide |Fatty acids, glycerol |Nucleotide | |Example |2o Amino acids |Glucose, Fructose, Ribose |Triglycerides |Adenine, Cytosine, Guanine | | | | |Steroids, Phospholipids |&Thymine/ Uracil | |Diagram | | | | | | | | | | | | | | | | | | | | | | | |Bonding (how units combine – |1st structure-strong covalent |Strong covalent glycoside |Rarely ever forms polymer |covalent bonds b/w sugar | |polymers ...
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...not to eat when I actually don’t need. When you go to a friend’s house and you had not planned to eat a meal there, don’t just sit and start eating. When you go to a party keep yourself busy with friends and skip a meal. Another habit to avoid when you are in the house is snacking. It’s important to try and occupy yourself with dishes or laundry, that way you’ll be less likely to mind having a snack. Multi-tasking while in the house with light household tasks will further help your calories burn and keeps your mind further away from snacking. More food, more calories, and more body fat. Keep your portions in check by choosing smaller serving dishes. If need *be, you can always go back for seconds. Chapter 6 forum Describe the functions of proteins in our bodies? How can you ensure that...
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...nutrients in your recipe. You may even be interested in minimizing some quantities (like calories or fat) or maximizing others (like carbohydrates or protein). Linear programming techniques can help to do this. For example, consider making a very simple trail mix from dry-roasted, unsalted peanuts and seedless raisins. Table 1 lists the amounts of various dietary quantities for these ingredients. The amounts are given per serving of the ingredient. Nutrient | Peanuts ServingSize = 1 Cup | Raisins ServingSize = 1 Cup | Calories (kcal) | 850 | 440 | Protein (g) | 34.57 | 4.67 | Fat (g) | 72.50 | 0.67 | Carbohydrates (g) | 31.40 | 114.74 | Suppose that you want to make at most 6 cups of trail mix for a day hike. You don’t want either ingredient to dominate the mixture, so you want the amount of raisins to be at least ½ of peanuts and the amount of peanuts to be at least ½ of the amount of raisins. You want the entire amount of trail mix you make to have fewer than 4000 calories, and you want to maximize the amount of carbohydrates in the mix. 1. Let x be the number of cups of peanuts you will use, let y be the number of cups of raisins you will use, and let c be the amount of carbohydrates in the mix. Find the objective function. 31.4x+114.74y=c 2. What constraints must be placed on the objective function? * x must be at least half of y. Denoted as y≥12x * y must be at least half of x. Denoted as x≥12y * Sum of x and y must not be greater...
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...material independently during the summer, it is expected that you have a solid understanding of these basic concepts for the start of this course. Prepare any specific questions that you may have. Again, this is an independent review and you will be expected to know these concepts for future use and assessment. This introductory material will not be covered in detail during class time. Chapter 1: Introduction: Themes in the Study of Life 1. Explain the importance of a biological hierarchy in terms of biological organization. 2. Why must scientists study the interactions of organisms with each other and the environment? 3. Comment on the relationship between structure and function in biology. 4. How specifically is the cell life’s basic unit of structure and function? 5. What is the significance of DNA to organisms? 6. Explain the basic concept of a biological feedback system. How does it work? 7. Explain briefly how life’s vast organisms are classified. Give the basic ideas. Make sure to include domains in your discussion. 8. Explain Darwin’s mechanism of evolutionary adaptation called natural selection. 9. Explain why “editing” is an appropriate metaphor for how natural selection acts on a population’s heritable variations. 10. Why do “science” and “inquiry” fit so...
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...Structures in All Eukaryotic Cells We're going to start with eukaryotic cells even though they tend to be more complex than prokaryotic. But, there is a method to our madness: you are a eukaryote and have eukaryotic cells, so we thought you might relate better. And, eukaryotic comes before prokaryotic alphabetically. Come up with whatever reasons you want for it, but eukaryotes are up first. Tough cookies. Eukaryotic Cell Structure and Function A cell is defined as eukaryotic if it has a membrane-bound nucleus. Any organism composed of eukaryotic cells is also considered a eukaryotic organism. Case in point: You. Biologists do not know of any single organism on Earth that is composed of both eukaryotic and prokaryotic cells. However, many different types of prokaryotic cells, usually bacteria, can live inside larger eukaryotic organisms. Creepy, but true. We humans, for example, have trillions of bacteria living in our colons, not to mention in our mouths and stomachs and small intestines and…you get the picture. Despite the fact that we have gobs of prokaryotic cells living inside and on us, humans are still categorically eukaryotic organisms. Deal with it. This means that all human cells, including those found in the brain, the heart, the muscles, and so on, are also eukaryotic. Here is what one of these little guys looks like: OK, we are slightly impressed. That is a lot of stuff jam-packed into something we can't see too well with the naked eye. All of...
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