Chapter Test Cell Cycle, Mitosis, and protein Synthesis
Key concepts you should understand about DNA:
DNA is a type of nucleic acid
DNA stands for Deoxyribonucleic Acid RNA is another type of nucleic acid The main job of
DNA is to store the information needed to build proteins.
The two main functions of proteins are to be structures and enzymes (workers).
The information used to build proteins is in the form of a code.
The code that stores information is made by the nitrogenous bases.
The four nitrogenous bases found in DNA are adenine, guanine, thymine, and cytosine.
A gene is a segment of DNA that codes for one protein. There are anywhere between 2000 to million nucleotides in a single gene A monomer is the building block of a macromolecule. The monomer that makes a nucleic acid is a nucleotide.
There are different nucleotides for DNA and for RNA. A nucleotide has three parts: a phosphate, a sugar (in DNA that is deoxyribose), and a nitrogenous base.
The order of nucleotides is the code that determines the protein that is made.
There are two strands of DNA in the molecule. These strands are held together by hydrogen bonds between the nitrogenous bases.
The two strands of DNA twist around each other making a helix shape.
The nucleotides in the same strand are held together by phosphate molecules. Alternating phosphate-sugar-phosphate.
Antiparallel means one strand of DNA runs one direction, while the other strand of DNA runs the other direction.
The genetic code is the order of the bases on all the strands of DNA of a Cell. A chromosome is one strand of DNA, it can hold between 500 to 1000 genes on it. If each gene is 5,000 nucleotides long, 500 X 5000 = 2,500,000 nucleotides in a short chromosome!
DNA holds the information for making proteins.
A single strand of DNA is called a Chromosome. A gene is a piece of DNA that codes for one protein. A single chromosome holds up to 1000 genes. A single gene has between 1000 to 100,000 nucleotides.
DNA is made out of nucleotides. A DNA nucleotide has three parts: a Phosphate, a deoxyribose sugar, and a nitrogenous base. There are four different types of nitrogenous bases: Adenine, Guanine, Thymine, and Cytosine.
A protein is made out of amino acids. The order of the amino acids determines the shape of the protein. The order of nucleotides determines the order of amino acids. The order of nucleotides is called the DNA code.
Ribosomes make proteins by using the DNA code. The DNA code is transferred to the ribosome from the nucleus by an mRNA molecule. mRNA is messenger RNA. mRNA is one of three types of RNA, the others are transfer RNA (tRNA) and ribosomal RNA (rRNA)
RNA and DNA are both nucleic acids. There are three differences between DNA and
RNA:
DNA has deoxyribose as its sugar, RNA has ribose as its sugar.
DNA has Thymine as one of its nitrogenous bases, RNA has Uracil instead.
DNA has two strands twisted together into a helix shape, RNA has a single strand that takes many shapes.
Transcription is the process of copying the code from a gene on DNA onto an mRNA strand.
RNA polymerase is the enzyme that makes the mRNA strand. There are three stages to transcription: Initiation, Elongation, and Termination.
RNA polymerase makes the mRNA by putting the complementary nucleotides in the bast right order at the pace of 40-80 nucleotides per second! The process of putting amino acids into an order based on the code found on mRNA is called translation. du? The nucleotides on an mRNA molecule are divided into groups of three nucleotides called codons. The nucleotides on a tRNA molecule form a shape that holds an amino acid on one side and reveals three nucleotides on the other. The three nucleotides are called an anticodon. grl o At the A-site of a ribosome the codon from the mRNA is matched to the anticodon from
lithe tRNA molecule.
Once they match, they move together to the P-site of the ribosome where the amino acid is released from the tRNA and attached to a chain of amino acids called a peptide chain. Once the amino acid is released, the mRNA and tRNA move to the E-site where the tRNA is released from the mRNA and ejected from the ribosome. This process repeats over and over until a stop codon hits the A-site of the ribosome. At this point the ribosome lets go of the mRNA chain. • The ribosome puts amino acids in the right order at the speed of 20 amino acids per second! When translation ends the peptide chain folds into a specific shape and is now a protein. so • There are 64 possible codon combinations and only 20 amino acids, this means several codon combinations code for the same protein. The mRNA is broken down into RNA nucleotides after translation, to be used again and again. Transcription is happening in hundreds of different places on the DNA strands at the same time in every cell. There are 30 trillion cells each with 46 strands of DNA holding about 1000 genes all having transcription occur hundreds of times simultaneously. • Here is a diagram of a ribosome:
Diagram
The Central Dogma of Biology is DNA makes RNA and RNA makes Proteins. It is considered the most important idea in all of Biology. Mutations are a change in the DNA sequence of a gene. They can cause a change in the order of amino acids. If the order of amino acids change, the shape of the protein will change. A change in the shape of the protein can cause it not to work properly. There are three types of mutations: Substitutions, Insertions, and Deletions. Substitution mutations are when one nucleotide replaces another nucleotide. Insertion mutations are when one nucleotide inserts itself between two existing bases. Deletion mutations are when one nucleotide is taken out from the existing bases. Insertions and Deletions are frameshift mutations causing all the codons (and often the amino acids) to change after the mutation. Substitution mutations only affect one codon and one amino acid. Mutations happen in a single cell if that cell is a cell in our body (somatic cell) it will only affect that cell. If it happens in our gametes (sperm or egg) it will affect every cell in the developing baby (embryo).
Key concepts you should understand about DNA:
DNA is a type of nucleic acid
DNA stands for Deoxyribonucleic Acid RNA is another type of nucleic acid The main job of
DNA is to store the information needed to build proteins.
The two main functions of proteins are to be structures and enzymes (workers).
The information used to build proteins is in the form of a code.
The code that stores information is made by the nitrogenous bases.
The four nitrogenous bases found in DNA are adenine, guanine, thymine, and cytosine.
A gene is a segment of DNA that codes for one protein. There are anywhere between 2000 to million nucleotides in a single gene A monomer is the building block of a macromolecule. The monomer that makes a nucleic acid is a nucleotide.
There are different nucleotides for DNA and for RNA. A nucleotide has three parts: a phosphate, a sugar (in DNA that is deoxyribose), and a nitrogenous base.
The order of nucleotides is the code that determines the protein that is made.
There are two strands of DNA in the molecule. These strands are held together by hydrogen bonds between the nitrogenous bases.
The two strands of DNA twist around each other making a helix shape.
The nucleotides in the same strand are held together by phosphate molecules. Alternating phosphate-sugar-phosphate.
Antiparallel means one strand of DNA runs one direction, while the other strand of DNA runs the other direction.
The genetic code is the order of the bases on all the strands of DNA of a Cell. A chromosome is one strand of DNA, it can hold between 500 to 1000 genes on it. If each gene is 5,000 nucleotides long, 500 X 5000 = 2,500,000 nucleotides in a short chromosome!
DNA holds the information for making proteins.
A single strand of DNA is called a Chromosome. A gene is a piece of DNA that codes for one protein. A single chromosome holds up to 1000 genes. A single gene has between 1000 to 100,000 nucleotides.
DNA is made out of nucleotides. A DNA nucleotide has three parts: a Phosphate, a deoxyribose sugar, and a nitrogenous base. There are four different types of nitrogenous bases: Adenine, Guanine, Thymine, and Cytosine.
A protein is made out of amino acids. The order of the amino acids determines the shape of the protein. The order of nucleotides determines the order of amino acids. The order of nucleotides is called the DNA code.
Ribosomes make proteins by using the DNA code. The DNA code is transferred to the ribosome from the nucleus by an mRNA molecule. mRNA is messenger RNA. mRNA is one of three types of RNA, the others are transfer RNA (tRNA) and ribosomal RNA (rRNA)
RNA and DNA are both nucleic acids. There are three differences between DNA and
RNA:
DNA has deoxyribose as its sugar, RNA has ribose as its sugar.
DNA has Thymine as one of its nitrogenous bases, RNA has Uracil instead.
DNA has two strands twisted together into a helix shape, RNA has a single strand that takes many shapes.
Transcription is the process of copying the code from a gene on DNA onto an mRNA strand.
RNA polymerase is the enzyme that makes the mRNA strand. There are three stages to transcription: Initiation, Elongation, and Termination.
RNA polymerase makes the mRNA by putting the complementary nucleotides in the bast right order at the pace of 40-80 nucleotides per second! The process of putting amino acids into an order based on the code found on mRNA is called translation. du? The nucleotides on an mRNA molecule are divided into groups of three nucleotides called codons. The nucleotides on a tRNA molecule form a shape that holds an amino acid on one side and reveals three nucleotides on the other. The three nucleotides are called an anticodon. grl o At the A-site of a ribosome the codon from the mRNA is matched to the anticodon from
lithe tRNA molecule.
Once they match, they move together to the P-site of the ribosome where the amino acid is released from the tRNA and attached to a chain of amino acids called a peptide chain. Once the amino acid is released, the mRNA and tRNA move to the E-site where the tRNA is released from the mRNA and ejected from the ribosome. This process repeats over and over until a stop codon hits the A-site of the ribosome. At this point the ribosome lets go of the mRNA chain. • The ribosome puts amino acids in the right order at the speed of 20 amino acids per second! When translation ends the peptide chain folds into a specific shape and is now a protein. so • There are 64 possible codon combinations and only 20 amino acids, this means several codon combinations code for the same protein. The mRNA is broken down into RNA nucleotides after translation, to be used again and again. Transcription is happening in hundreds of different places on the DNA strands at the same time in every cell. There are 30 trillion cells each with 46 strands of DNA holding about 1000 genes all having transcription occur hundreds of times simultaneously. • Here is a diagram of a ribosome:
Diagram
The Central Dogma of Biology is DNA makes RNA and RNA makes Proteins. It is considered the most important idea in all of Biology. Mutations are a change in the DNA sequence of a gene. They can cause a change in the order of amino acids. If the order of amino acids change, the shape of the protein will change. A change in the shape of the protein can cause it not to work properly. There are three types of mutations: Substitutions, Insertions, and Deletions. Substitution mutations are when one nucleotide replaces another nucleotide. Insertion mutations are when one nucleotide inserts itself between two existing bases. Deletion mutations are when one nucleotide is taken out from the existing bases. Insertions and Deletions are frameshift mutations causing all the codons (and often the amino acids) to change after the mutation. Substitution mutations only affect one codon and one amino acid. Mutations happen in a single cell if that cell is a cell in our body (somatic cell) it will only affect that cell. If it happens in our gametes (sperm or egg) it will affect every cell in the developing baby (embryo).
