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51 Cards in this Set
- Front
- Back
The genetic source of diversity among cells is ________________ ____
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deoxyribonucleic acid
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The primary function of DNA is to:
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- Store and transmit genetic information that tells cells
which proteins to make and when to make them |
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DNA is made of repeating subunits called ___________
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nucleotides
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A DNA nucleotide has 3 parts:
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- A sugar called deoxyribose
- A phosphate group made of phosphorus and oxygen - A nitrogen-containing base |
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The four types of Nitrogen containing bases are:
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- Adenine
- Guanine - Cytosine - Thymine |
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In 1953, ______ and _____ suggested a model for DNA
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Watson and Crick
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The model is composed of two __________ ______ that wrap around each other to form a ______ ______. This is called a ______ _____
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nucleotide chains; double spiral; double helix
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Individual nucleotides are connected by covalent bonds between ___________ and _________
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deoxyribose and phosphate
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The bases attach and face toward the ______ of the helix
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center
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The bases of each chain are linked together by ________ bonds; this is a ____ bond
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hydrogen; weak
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Cytosine pairs with _______
Adenine pairs with _______ These pair of bases are called _____________ ____ _____ |
guanine
thymine complementary base pairs |
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The nucleotide sequence in one nucleotide chain is an exact __________ of the nucleotide sequence in the other chain
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complement
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The ability of DNA to make exact copies of itself is important because:
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cells that divide must pass exact copies of their DNA to offspring cells
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the process of copying DNA in a cell
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Replication
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During replication, the 2 nucleotide chains separate by _________, and each chain serves as a _______ for a new nucleotide chain
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unwinding; template
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The first step in replication is __________ of the 2 nucleotide chains
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separation
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The point at which the 2 chains separate is called the ___________ ____
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replication fork
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The chains are separated by enzymes called _________
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helicases
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The enzymes break the ________ _____ between the bases, and the chains separate
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hydrogen bonds
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Enzymes called ___ ___________ then bind to the separated chains
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DNA polymerases
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New chains of DNA are assembled using ___________ in the surrounding ______ that are complementary to the existing DNA chains
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nucleotides; medium
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___ ___________ occurs simultaneously at many points along the separated chains
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DNA replication
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When replication is completed, _ new exact copies of the original DNA molecule are produced and the cell is ready to undergo ____ ________
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2; cell division
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The process of DNA replication occurs with a high degree of accuracy about 1 error in every __,___ paired nucleotides
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10,000
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Change in the nucleotide sequence at even once location
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Mutation
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DNA proofreading and repair process brings the errors rate down to 1 error per every _______ nucleotides
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billion
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Abnormal DNA structure can be recognized and repaired by specific _______
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enzymes
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DNA can be damaged by a variety of agents such as _________ and __ _________
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chemicals and UV radiation
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The nucleic acid ___________ ____ (___) is responsible for the movement of genetic information from DNA in the nucleus to the side of protein synthesis in the cytosol
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ribonucleic acid (RNA)
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RNA is a _______ ____ made of repeating ___________
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nucleic acid; nucleotides
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Each RNA molecule is composed of the _____ ______, instead of ___________
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sugar ribose; deoxyribose
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A 2nd difference is that _______ is rarely a part of an RNA molecule
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thymine
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______, a nitrogen-containing base, usually replaced thymine. As a result, uracil pairs with _______ in RNA
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Uracil; adenine
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3 types of RNA:
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- Messenger (mRNA)
- Transfer (tRNA) - Ribosomal (rRNA) |
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consists of RNA nucleotides in the form a single uncoiled chain. It carries genetic information from the DNA in the nucleus to the cytosol of a eukaryotic cell
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Messenger RNA (mRNA)
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mRNA is grouped as 3 letter sequences called ______
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codons
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There are __ possible codons
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64
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The process by which genetic information is copied from DNA to mRNA is _____________
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transcription
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consists of a single chain of about 80 nucleotides folded into a hairpin shape that bind to specific amino
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Transfer RNA (tRNA)
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tRNA is grouped together in 3 letter sequences called __________
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anticodons
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Anticodons code for specific amino acids, but are based upon the codons of the ____
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mRNA
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The process by which genetic information is copied from mRNA to tRNA is ___________
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translation
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_________ ___ (____) is the most abundant form of RNA
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Ribosomal RNA (rRNA)
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RNA molecules are in ________ form. They make up the ribosomes where ________ are made
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globular; proteins
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____ provides a translation of the amino acid sequence to the ____ so that the ribosomes can produce the necessary proteins
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tRNA; rRNA
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The production of protein is called _______ _________
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protein synthesis
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The amount and kind of proteins that are produced in a cell determine the _________ and ________ of the cell
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structure and function
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Proteins are made of one or more ____________, each of which consists of a specific sequence of _____ _____ linked together by _______ _____
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polypeptides; amino acids; peptide bonds
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The polypeptides that make up one protein may consist of hundreds or thousands of the __ amino acids arranged in a particular sequence
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20
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The function of a protein depends on its:
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ability to bind with other molecules within a cell
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The polypeptide chain represents the protein's _______ _________
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primary structure
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