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SpontaneousOnyx3552

Uploaded by SpontaneousOnyx3552

University of the Immaculate Conception

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protein biochemistry amino acids protein synthesis biology

Summary

These lecture notes provide an overview of proteins and amino acids, including their functions, types, digestion, and synthesis.

Full Transcript

Proteins: Amino Acids Protein Functions in body Building materials for growth (collagen-tissues, bones and teeth) Enzymes Hormones Fluid balance (albumin) Transporters (Hemoglobin and other carrier proteins) Antibodies (Immunoglobulins) Energy source (gluconeoge...

Proteins: Amino Acids Protein Functions in body Building materials for growth (collagen-tissues, bones and teeth) Enzymes Hormones Fluid balance (albumin) Transporters (Hemoglobin and other carrier proteins) Antibodies (Immunoglobulins) Energy source (gluconeogenesis) Amino Acids Side groups Amino Acids Nonessential amino acids Body can synthesize from nitrogen and fragments of CHO and lipids Essential amino acids Body cannot make in sufficient amounts Conditionally essential amino acids Nonessential amino acid becomes essential under special circumstances (Tyrosine from PKU) Dipeptide Condensation reaction Proteins Polypeptide Proteins Amino acid sequences Determines the shape of the polypeptide chain Shape impacts function Variety of sequences Protein shape and function Proteins Protein denaturation Change in a protein’s shape Change in shape leads to function Causes of denaturation Heat Agitation Acid Base Alcohol Heavy metals (mercury and silver)- milk is the antidote Protein Digestion Mouth Stomach Hydrochloric acid denatures proteins Pepsinogen to pepsin Small intestine Hydrolysis reactions Peptidase enzymes Protein Digestion Amino Acid Transport Absorption of AAs Systems: Secondary active transport driven by Na+ gradient Facilitated diffusion Protein Synthesis DNA template to make mRNA Transcription mRNA carries code to ribosome Ribosomes are protein factories mRNA specifies sequence of amino acids Translation tRNA Sequencing errors Disorders/Inborn errors of Protein Metabolism Protein Synthesis Roles of Proteins Growth and maintenance Building blocks for most body structures Collagen Replacement of dead or damaged cells Enzymes Break down, build up, and transform substances Catalysts Roles of Proteins Roles of Proteins Hormones Messenger molecules Transported in blood to target tissues Regulators of fluid balance Edema Acid-base regulators Attract hydrogen ions Transporters – specificity Roles of Proteins Roles of Proteins Antibodies Defend body against disease Specificity Immunity – memory Energy and glucose Starvation and insufficient carbohydrate intake Other roles Preview of Protein Metabolism Protein turnover & amino acid pool Continual production and destruction Amino acid pool pattern is fairly constant Used for protein production Used for energy – if stripped of nitrogen Nitrogen balance Zero nitrogen balance Positive and negative nitrogen balance Preview of Protein Metabolism Excreting urea Liver releases urea into blood Kidneys filter urea out of blood Liver disease Kidney disease Protein intake and urea production Water consumption Preview of Protein Metabolism Protein Regulations for Food Labels Quantity of protein in grams Percent Daily Value Not mandatory Protein claims Consumption by children under 4 years old Quality of protein Protein Quality Reference protein Preschool-age children High-quality proteins Animal proteins Plant proteins Complementary proteins Low-quality proteins combined to provide adequate levels of essential amino acids Protein Quality Two factors Digestibility Other foods consumed Animal vs. plant proteins Amino acid composition Essential amino acid consumption Nitrogen-containing amino groups Limiting amino acid Preview of Protein Metabolism Making fat Energy and protein exceed needs Carbohydrate intake is adequate Can contribute to weight gain Deaminating amino acids Stripped of nitrogen-containing amino group Ammonia Keto acid Preview of Protein Metabolism Making other compounds Neurotransmitters Melanin Thyroxin Niacin Energy and glucose Wasting of lean body tissue Adequate intake of carbohydrates and fats Protein Quality Reference protein Complementary proteins Combining different amino acids to provide all essential amino acids Protein-Energy Malnutrition (PEM) Insufficient intake of protein, energy, or both Prevalent form of malnutrition worldwide Impact on children Poor growth Most common sign of malnutrition Impact on adults Conditions leading to PEM END OF SECTION 5_CHON

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