BIOCHEMISTRY REVIEW Biochemistry ______________ is a unique element with the remarkable ability to form strong, stable chemical bonds with many different types of atoms. Macromolecules are molecules made from repeating subunits called __________________ The four major macromolecules in living cells are carbohydrates, lipids, proteins, and nucleic acids The chemical mechanisms for making and breaking polymers are similar for all macromolecules. - ___________________ is building large polymers - Digestion is breaking down large polymers. Polymers are built through a process called dehydration synthesis, which connects monomers together by removing a ______________ molecule. Biological Molecules ____________________ are the main source of energy in living cells. Monosaccharides, single sugar molecules, are the monomer units of carbohydrates. - Glucose (blood sugar) - Galactose (milk sugar) - Fructose (fruit sugar) Polysaccharides are large macromolecules formed from monosaccharides. Excess sugar is stored as polysaccharieds called ____________________. _________________ are polymers made from fatty acids and glycerol. They include fats, oils, and waxes. - store energy - biological membranes - waterproof coverings - chemical messengers (e.g. steroids) _____________________ are polymers made from amino acids. These molecules are instrumental in about everything that an organism does. - Antibodies - Enzymes - Messengers - Structural - Transport/Storage ____________________ store and transmit hereditary or genetic information. - DNA is Deoxyribonucleic Acid - RNA is Ribonucleic Acid - The monomers of nucleic acids are called nucleotides. DNA Structure DNA contains the hereditary information called genes. —DNA stands for _____________________ acid —DNA is a double ____________ —DNA has four bases Adenine, ______________, Cytosine, and ______________ DNA Replication Replication occurs before cells divide, because all cells need their own copy of ________. DNA replication is considered semi-conservative. _____________ “unzips” the double stranded DNA. _________________ attaches complementary bases to each strand in the 5’ – 3’ direction. Okazaki fragments are a result of replication on the lagging strand of DNA. Multicellular Organisms Multicellular organisms contain many different kinds of __________ that are specialized for the type of work they do; this is called cell specialization. Regulation of Gene Expression Almost every cell in an organism carries the exact same ______. Controlling which genes are expressed results in differentiated cells. Cells control gene expression by regulating which sections of DNA are transcribed into _______. The Central Dogma of Genetics Transcription and Translation: the two step process of turning DNA into proteins. —The DNA can stay ____________ in the nucleus. —Many ______________ can be created from one DNA template. —Allows for more ____________ over which genes are expressed. RNA RNA has three main differences from DNA: —A slightly different _________ than DNA —Base ________ (U) in place of thymine (T) —Single ____________ The Process of Transcription: Transcription occurs in the _____________. The enzyme helicase “unzips” the DNA strands and RNA polymerase copies one strand of DNA into a complementary mRNA strand. The mRNA travels out of the nucleus to the ribosome. The Process of Translation: Translation occurs at the ________________. The ribosome begins translation at the start codon AUG. The ribosome reads the mRNA three bases at a time. The __________________ are carried to the ribosome by the tRNA molecule that has an anticodon complementary to the mRNA codon. Amino acids are attached one at a time forming a complex folded polypeptide (protein). The ribosome will continue translating the protein until it reads one of the three stop codons. Modifying the mRNA Transcript Genes are made of parts represented in the mRNA (exons) and parts that are transcribed but not present in the mRNA (introns). In some genes more than 90% of the transcript is made of ____________ and will be spliced from the mRNA. Triplet Code There are only four bases in the genetic code Adenine, Uracil, Guanine, and Cytosine. These bases combine in ____ three-base configurations to code for ____ different amino acids. Gene Mutations Changes in the DNA sequence that affect genetic information. Gene mutations result from both spontaneous and induced mutation.