PROTEIN SYNTHESIS and METABOLISM Protein Synthesis Gene Expression
PROTEIN SYNTHESIS and METABOLISM
Protein Synthesis (Gene Expression) Notes Proteins (Review) • Proteins make up all living materials
• Proteins are composed of amino acids – there are 20 different amino acids • Different proteins are made by combining these 20 amino acids in different combinations
• Proteins are manufactured (made) by the ribosomes
• Function of proteins: 1. Help fight disease 2. Build new body tissue 3. Enzymes used for digestion and other chemical reactions are proteins (Enzymes speed up the rate of a reaction) 4. Component of all cell membranes
MAKING PROTEINS Step 1: Transcription
• First Step: Copying of genetic information from DNA to RNA called Transcription Why? DNA has the genetic code for the protein that needs to be made, but proteins are made by the ribosomes—ribosomes are outside the nucleus in the cytoplasm. DNA is too large to leave the nucleus (double stranded), but RNA can leave the nucleus (single stranded).
• Part of DNA temporarily unzips and is used as a template to assemble complementary(matching) nucleotides into messenger RNA (m. RNA).
• When the RNA is made, there is one change that is different between them. Instead of a T(thymine), RNA has a U(uracil). • Anytime in RNA that you would see a T, instead it will be a U.
• m. RNA then goes through the pores of the nucleus with the DNA code and attaches to the ribosome.
MAKING PROTEINS Step 2: Translation
Making a Protein—Translation • Second Step: Decoding of m. RNA into a protein is called Translation. • Transfer RNA (t. RNA) carries amino acids from the cytoplasm to the ribosome.
These amino acids come from the food we eat. Proteins we eat are broken down into individual amino acids and then simply rearranged into new proteins according to the needs and directions of our DNA.
• A series of three adjacent(in a row) bases in an m. RNA molecule codes for a specific amino acid—called a codon. • Each t. RNA has 3 nucleotides that are complementary(match up) to the codon in m. RNA. Amino acid • Each t. RNA codes for a different amino acid. Anticodon
• m. RNA carrying the DNA instructions and t. RNA carrying amino acids meet in the ribosomes.
• Amino acids are joined together to make a protein. Polypeptide = Protein
ACTIVITY 2 2 nd Base 3 rd Base 1 st Base CODON CHART
CODON CHART 2 Methionine Asparagine Aspartic Acid Stop
Protein Synthesis
What is Metabolism? • It is the sum of all life sustaining(keeping you alive) chemical reactions within all living organisms.
Example: Cellular Respiration The conversion of Glucose and oxygen into water, carbon dioxide and ATP requires a chemical reaction C 6 H 12 O 6 + O 2 �� 2 O H+ CO 2 + ATP
3 Categories • Converting food into energy • Converting food into necessary building blocks • Elimination of waste
Converting food into energy The conversion of Glucose and water into oxygen, carbon dioxide and ATP requires a chemical reaction C 6 H 12 O 6 + O 2 �� H 2 O + CO 2 + ATP CHEMICAL REACTION
Converting food into building blocks Macromolecules = large molecules (polymers), made up of smaller sub units (monomers) Example: proteins (polymer) are made up of many amino acids (monomers) strung together. Ser – Phe – Leu – Gly – Ala – Phe – His
Macromolecules in living organisms Carbohydrates �Monomer(single unit) = monosaccharide �Ex. Sugars like glucose, lactose �Polymer(multiple unit) = polysaccharide �Ex. Starchs like bread, pasta, veges �What do they do? - short-term energy storage - easy to break down - structural support
Molecules in living organisms Proteins �Monomers = amino acids �Polymer = proteins �What do they do? - chemical reactions (enzymes) - growth/repair of cells/tissues - structural support/movement - hormones �Examples -meat, eggs, beans, peanut butter -enzymes
Molecules in living organisms Lipids • Monomer = fatty acid • Polymer = Lipid • What do they do? - Long-term energy storage - Hard to break down (won’t dissolve in water) - Cell structure (membrane) • Examples - fats, oils and butter - wax - steroids (cholesterol)
Molecules in living organisms Nucleic Acids • Monomer = nucleotide • Polymer = nucleic acids • What do they do? -contain instructions on how to build proteins • Examples - DNA - RNA
Elimination of waste Byproducts(things that also result from processes) are converted into useful molecules or eliminated(gotten rid of) entirely from the body Examples: Oxygen produced by plants is used in cellular respiration Breakdown of proteins in food creates ammonia as a waste product which is eliminated through urine
Enzymes • Special type of protein • Speeds up chemical reactions in the body • Breaks molecules apart or puts them together
Example Lactose is a macromolecule (carbohydrate made of glucose and galactose) Lactase is an enzyme that breaks apart lactose
ACTIVITY 3 AMOEBA SISTERS Watch the video and complete activity 3 in the packet for maximum fun(and points) https: //www. youtube. com/watch? v=qg. VFk. Rn 8 f 10&t=145 s
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