PowerPoint Presentation

PROTEINS. Definition of Proteins Protein Structure Classification of Proteins Function of Proteins Glycoproteins Amino Acids as Buffers Essential and Non-essential Amino Acids Digestion of Proteins.

LEARNING OUTCOMES. Describe the structure and functions of proteins. Discuss the different classes of proteins based on structure. Explain the functions and clinical significance of proteins. Relate the buffer ability of amino acid to its structure. Differentiate essential and non-essential amino acids. Explain how proteins are digested and absorbed..

PROTEINS & STRUCTURE.

PROTEINS. highly complex molecules that are actively involved in the most basic and important aspects of life. MONOMER: Amino Acids (building blocks) POLYMER: Polypeptides (chains of amino acids linked by peptide bonds).

STRUCTURE OF PROTEINS. Protein: Discovery, Characteristics, and Structures : Plantlet.

Proteins are large, complex molecules formed by one or more twisted and folded strands of amino acids. Primary (first level) –sequence of amino acids in a chain. Secondary (secondary level) – formed by folding and twisting of the amino acid chain. Tertiary (third level) –formed when the twists and folds of the secondary structure fold again to form a larger three-dimensional structure. Quaternary (fourth level) –protein consisting of more than one folded amino acid chain..

FUNCTION OF PROTEINS.

FUNCTION OF PROTEINS. 1. ENZYME ACTION - Enzymes are proteins that conduct specific chemical reactions. An enzyme’s job is to provide a site for a chemical reaction and to lower the activation energy..

FUNCTION OF PROTEINS. 2. PEPTIDE HORMONES- Hormones are chemical messengers that communicates a message to initiate a specific reaction or cellular process. Examples of hormones produced from proteins: INSULIN - secreted by the β cells of the pancreatic islets of Langerhans and maintains normal blood glucose levels by facilitating cellular glucose uptake, regulating carbohydrate, lipid and protein metabolism and promoting cell division and growth through its mitogenic effects..

FUNCTION OF PROTEINS. GLUCAGON - secreted from the alpha cells of the pancreatic islets of Langerhans. Hypoglycemia is physiologically the most potent secretory stimulus and the best known action of glucagon is to stimulate glucose production in the liver and thereby to maintain adequate plasma glucose concentrations..

FUNCTION OF PROTEINS. MELATONIN - a hormone secreted by the enigmatic pineal gland in response to darkness; plays a role in managing sleep-wake cycle and circadian rhythm. THYROID HORMONE – hormones in charge of controlling metabolism, growth, and many other bodily functions..

FUNCTION OF PROTEINS. 3. FLUID AND ELECTROLYTE BALANCE- the hydrophilic property of proteins ensure even water distribution between blood and other cells. Insufficient protein (albumin and other proteins) in the blood causes fluid retention or edema (swelling)..

FUNCTION OF PROTEINS. 4. pH BALANCE- maintains proper pH in the blood (between 7.35 and 7.45) which is slightly basic. Even a slight change in blood pH can affect body functions. If the blood becomes too acidic (acidosis), it means that the level of hydrogen (H+) in the blood is excessive. If the blood becomes too basic/alkaline (alkalosis), it means that the level of H+ in the blood is deficient..

FUNCTION OF PROTEINS. 5. TRANSPORT- Some proteins act as channels that allow particular molecules to move in and out of cells through the cell membrane (facilitated diffusion). Others (Carrier proteins) act as one-way taxis and require energy to function..

FUNCTION OF PROTEINS. 6. ANTIBODIES- When a foreign substance attacks the body, the immune system produces antibodies, special proteins that recognize a unique molecule on harmful bacteria and viruses known as an antigen. Antibodies bind to the antigen and destroy it..

FUNCTION OF PROTEINS. 7. WOUND HEALING, TISSUE REGENERATION, AND NERVE FUNCTION- Proteins are involved in all aspects of wound healing. Bradykinin - dilate blood vessels at the site of injury. Fibrin - secure platelets that form a clot to stop the bleeding. Collagen fibers – mend injured tissue.

FUNCTION OF PROTEINS. Tissue regeneration is the creation of new cells (cell division), which requires many different proteins including enzymes, transport proteins, hormones, and collagen. The cells lining the intestine regenerate every three to five days. Protein-inadequate diets impair tissue regeneration, causing many health problems including impairment of nutrient digestion and absorption. Amino acids can be used to make neurotransmitters (e.g., epinephrine) that transmit messages from one nerve cell to another..

FUNCTION OF PROTEINS. 8. ENERGY SOURCE- If a person’s diet does not contain enough carbohydrates and fats, proteins from the blood and body tissues undergo deamination, a process where the amine group is removed from the amino acid and the nitrogen is transported to the kidney for excretion. The remaining components are metabolized for energy..

FUNCTION OF PROTEINS. Important Reminder: To protect our body tissues from being broken down for energy, it is important to eat an adequate amount of fat and carbohydrate. Our body cannot store excess protein. Excess protein intake results in nitrogen excretion; the remaining components are used for energy or converted to fat for later use..

GLYCOPROTEINS.

GLYCOPROTEINS. Glycoprotein - The Definitive Guide | Biology Dictionary.

GLYCOPROTEINS. The protein’s polypeptide side chains are covalently joined to the carbohydrate, an oligosaccharide chain (glycan). Glycoconjugates are formed when carbohydrates are linked to proteins and lipids. They exist in three forms: Glycoproteins - formed when the protein component predominates in the combination of carbohydrates and proteins. Glycolipids - formed when a carbohydrate combines with lipids. Proteoglycans - the association comprises more carbohydrates than proteins..

GLYCOPROTEINS. The removal of a hydroxyl group (-OH) from a monosaccharide in a polysaccharide chain forms a glycosyl group that is unstable Attachment to amino acids stabilize it as the hydroxyl group of the associated amino acid replaces the lost –OH of the glycosyl group. Adding glycosyl to a peptide chain, protein, or lipid is called glycosylation. In eukaryotic cells, glycosylation occurs in the endoplasmic reticulum and Golgi apparatus..

GLYCOPROTEINS. glycosylation glycans glycoproteins glycoprotein glycoconjugates.

GLYCOPROTEINS. EXAMPLES OF GLYCOPROTEINS. Serum glycoproteins – found in blood plasma, too high or too low amounts can be indicators of possible conditions or diseases, e.g. cartilage oligomeric matrix protein (COMP) and hepatocyte growth factor activator (HGFA) are markers linked to arthritis and fibrosis, respectively..

GLYCOPROTEINS. EXAMPLES OF GLYCOPROTEINS. 2. Zona Pellucida Glycoprotein– surrounds human egg cells and regulates how and whether a sperm cell can bind to and move into released, unfertilized eggs. It has four glycoproteins (ZP1 through to 4) known to contribute to egg/sperm interaction. Recent studies show that infertile females often have a mutation in the gene that encodes for ZP1..

GLYCOPROTEINS. EXAMPLES OF GLYCOPROTEINS. 2. Zona Pellucida Glycoprotein (ZP 1 to ZP4– surrounds human egg cells and regulates how and whether a sperm cell can bind to and move into released, unfertilized eggs. Recent studies show that infertile females often have a mutation in the gene that encodes for ZP1..

GLYCOPROTEINS. EXAMPLES OF GLYCOPROTEINS. 3. Cartilage glycoprotein – Glycoproteins in structural tissues help the main components – in the case of cartilage, collagen and fibrinogen – form a strong, fibrous network and hold more water. Research tells us that an excessively high level of the human cartilage glycoprotein YKL-40 is responsible for faulty cartilage remodeling in patients with osteoarthritis..

GLYCOPROTEINS. EXAMPLES OF GLYCOPROTEINS. 4. Mucin-type glycoprotein– Glycoproteins play a major role in innate immunity, hydration, lubrication, and enzyme activity – most mucus contains antimicrobial enzymes. Mucins, (result of O-linked oligosaccharides) can be found in the airway, digestive system, sweat glands, breasts, and even cancer cells. Mucin is a natural barrier that protects the environment surrounding the tissues and cells it is formed by..

GLYCOPROTEINS. EXAMPLES OF GLYCOPROTEINS. 5. Glycoprotein hormones – these are examples of glycoprotein hormones: Follicle-stimulating hormone (FSH) – controls the menstrual cycle and the production of eggs by the ovaries. Luteinizing hormone - secreted by the anterior pituitary gland; stimulates ovulation in females and the synthesis of androgen in males. Thyroid-stimulating hormone - stimulates the production of the thyroid hormones, thyroxine (T4) and triiodothyronine (T3), by the thyroid gland.

GLYCOPROTEINS. EXAMPLES OF GLYCOPROTEINS. 6. Immune glycoprotein – Any immune cell has receptors that bind to certain secreted glycoproteins on the membranes of other cells. The coronavirus spike glycoprotein (sialic acid) on the its surface increases production of three immune receptors: SIGLEC5, SIGLEC9, and SIGLEC11 (short-term immune response not specific to the virus). This delays the immune response, allowing the virus to reproduce further..

GLYCOPROTEINS. EXAMPLES OF GLYCOPROTEINS. 7. Glycoprotein IIb IIIa Inhibitors - associated with the blood clotting response. When these two glycoproteins block glycoprotein IIb and IIIa receptors, platelets cannot clump together to form a clot. Medications based on this principle are used during certain types of coronary artery procedures to prevent blood clot formation..

AMINO ACIDS AS BUFFERS.

AMINO ACID STRUCTURE. Amine group (Base). Carboxyl group (Acid).

AMINO ACIDS AS BUFFERS. Blood pH | BioNinja.

ESSENTIAL AND NON-ESSENTIAL AMINO ACIDS.

ESSENTIAL AND NON-ESSENTIAL AMINO ACIDS. CHARACTERISTICS ESSENTIAL NON-ESSENTIAL DEFINITION/SOURCE Cannot be produced by the body and should be acquired through food Synthesized by the body from other amino acids and biomolecules NUMBER OF AMINO ACIDS 9 amino acids out of 20 are thought to be essential 11 of the 20 amino acids are non-essential ROLE Serves to build and repair muscle tissues precursor molecules for the formation of neurotransmitters in the brain Removal of toxins integral in the synthesis of RBC and WBC promotes brain function.

ESSENTIAL AND NON-ESSENTIAL AMINO ACIDS. ALANINE ASPARAGINE ASPARTIC ACID GLUTAMIC ACID ARGININE CYSTEINE GLUTAMINE TYROSINE GLYCINE PROLINE SERINE C$SSSOCädAL HISTIDINE LYSINE METHIONINE PHENYLALANINE THREONINE TRYPTOPHAN ISOLEUCINE LEUCINE VALINE.

DIGESTION AND ABSORPTION OF PROTEINS.

Liver *nine geiås éseoed peel vein to the Iker. Fsom the•e they eter the bloodstream. Little d' protein is present in Stocnoch Pancreas Sino tntestiru• Anus Partial protein &gestion by the enzyme pepsin ond stomach acid protein digestion by enzymes released by the pancreas Pinal digestion of pstein to amie acids takes place mostly inside cells of the smal intestin..

In the Stomach: . : —II YEI pepsin Exocrine Pancreas secretlcn Into the Small Intestine: [trypsinogen ittypsrn praG1boxypepiMdas,es carboxypeptidæses Secretion by the Brush Border Of the Srnäll Intestine:.