Proteins: Chemical Blocks of Life PDF

CHEMICAL BLOCKS OF LIFE: PROTEINS By: Dr. Yasmine Amr Issa Associate Professor of Medical Biochemistry and Molecular Biology Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology ...

CHEMICAL BLOCKS OF LIFE: PROTEINS By: Dr. Yasmine Amr Issa Associate Professor of Medical Biochemistry and Molecular Biology Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  DEAR STUDENTS & Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  TRANSFER GOAL Understand the role of proteins as nutrients, building blocks and players in health and disease. Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  STUDENTS’ LEARNING OUTCOMES(SLOs) At the end of this session, the student will be able to: Understand how proteins help us function and survive Describe the building blocks of proteins Discuss proteins’ role in health and disease Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  Question: What is a common component in all those photos? Cell membrane Antibodies Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  Answer: They all contain PROTEINS Cell membrane Antibodies Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  QUESTION: FROM THE PREVIOUS SLIDE, WHAT DO YOU THINK FUNCTIONS OF PROTEINS INCLUDE? Structural Messengers for function (Hair, conveying nails, skin) signals Growth and Fight developme nt Numerous Functions infections (antibodies) and the list goes on! Enzymatic Transport Blood clotting Contractile reactions in blood function (hemoglobi (Muscles) n, albumin) Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  DIETARY SOURCES OF PROTEINS Animal sources Plant sources Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  QUESTION: CAN PROTEINS BE USED READILY AS A SOURCE OF ENERGY LIKE CARBOHYDRATES AND LIPIDS? Although 1 gram of protein gives 4 calories, however since proteins are precious molecules performing various functions, they are not broken down for energy production except in extreme conditions (starvation, cancer). Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  BUILDING BLOCKS OF PROTEINS: AMINO ACIDS Building blocks of protein There are 20 naturally occurring amino acids that cells use to make proteins , called primary aminoacids Basic structure is a central carbon, an amino group and a carboxylic group. In addition, a side chain( R ) distinguishes the a.a chemically Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  HOW DO AMINO ACIDS BUILD PROTEINS? Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  EXAMPLES OF DIFFERENT SIDE CHAINS Sulfur containing Iminoacid: amino acids Proline is the only iminoacid as Methionine and cysteine it contains imino (NH) rather than amino (NH2) group.. Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  Branched chain amino acids Hydroxyl containing amino They have branched side acids chain. They include: Valine, Include: Serine, threonine and leucine and isoleucine. tyrosine. Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  CLASSIFICATION OF AMINO ACIDS According to structure According to charge According to biological importance According to polarity Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  CLASSIFICATION OF AMINO ACIDS Aliphatic According to structure According to charge Aromatic According to biological importance According to polarity Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  Q.Which of the following aminoacids is an aromatic aminoacid? A) Phenylalanine B)Valine C)Leucine D)Isoleucine Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  CLASSIFICATION OF AMINO ACIDS Neutral According to structure Basic (positively charged at physiologic pH According to charge Acidic (negatively charged at physiologic pH According to biological importance According to polarity Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  Q.Which of the following aminoacids is a basic aminoacid? A) Glutamic B)Aspartic C)Arginine D)Glycine Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  CLASSIFICATION OF AMINO ACIDS Essential Can’t be synthesized in the body According to structure and must be supplied in diet Non- Essential According to charge Can be synthesized in the body According to biological Semi- Essential importance Can be synthesized in the body but with a small quantity that is not enough in case of increased According to polarity requirements (e.g growth) Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  CLASSIFICATION OF AMINO ACIDSPolarity is the ability of the amino acid side chain to gain or lose protons or According to structure participate in hydrogen or ionic bonds According to charge Non-Polar Hydrophobic- always neutral According to biological importance Polar Hydrophilic- Can be neutral, acidic, basic According to polarity Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  SIGNIFICANCE OF POLARITY IN AMINOACIDS. Gives the Help protein anchor its 3D the shape protein to cell membran e and connect exterior to Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  CLINICAL IMPLICATION (SICKLE CELL ANEMIA) Glutamic acid is a Valine is a non- polar amino acid polar amino acid Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  AMPHOTERIC PROPERTY OF AMINO ACIDS Precipitates if placed in a media with an electric current at the isoelectric point The pH at which this occurs is called ISOELECTRIC POINT In solution, amino acids can behave On complete ionization of neutral as acids and alkalis due to the amino acids as dipolar ions presence of acidic group (-COOH) and (Zwitterions), they carry both basic group negative and positive charges, which (-NH Dr. Yasmine Amr Issa- Associate Professor 2). Biochemistry and Molecular Biology of Medical are equal.  PROTEINS IN DISEASE Aminoacids can synthesize neurotransmitters (GABA), hormones (Thyroid hormone), Melanin (Pigment of hair and skin). Deficiency can lead to diseases. Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  Branched chain amino acids used in treatment of liver diseases (Valine- Leucine-Isoleucine) Sulfur containing amino acids (Cysteine, Methionine) Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  Excessive amino acids Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology intake  Deficiency of Deficiency of clotting Defects in hemoglobin immunoglobulins factors Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  TAKE-HOME MESSAGE Proteins are diverse molecules with plenty of roles in health and disease Amino acids are the building blocks of proteins Amino aicds can be classified according to their structure, charge, biological importance and polarity Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  Lecture notes Portal resources Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology  DEAR STUDENT: Don’t forget to complete your KWL chart And reflect on your learning experience by writing down what do you learnt from the lecture (3 points at least) Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology Dr. Yasmine Amr Issa- Associate Professor of Medical Biochemistry and Molecular Biology