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34 Cards in this Set
- Front
- Back
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Life depends on the ability... |
To store, retrieve, and translate the genetic instructions required to make and maintain a living organism. |
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Proteins perform most of the cell's function by? |
serve as building blocks for cell structures, form enzymes that catalyze the cell's chemical reactions, regulate activity of genes, and enable cells to move and communicate with one other. |
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How is DNA the genetic material? |
LIfe requires instruction to be passed from one generation to the next. DNA perfoms these functions. |
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Discuss the chains of DNA |
A molecule of DNA consists of 2 long polynucleotide chains. Each chain/strans is composed of 4 types of nucleotide subunits, and the 2 strands are held together by hydrogen bonds between the base portions of the nucleotides |
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What did griffith's findings set the stage for? |
Providing the first strong evidence that genes are made of DNA |
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What did the Hershey experiment conclude |
The experiment demonstrated conclusively that viral DNA enters bacterial host cells, whereas viral proteins does not. Genetic material in the virus had to be made of DNA. |
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In DNA what are nucleotides composed of/ |
Nucleotides are composed of a nitrogen-containing base and a 5carbon sugar thats attatched to one or more phosphate groups |
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What is the alternating structure of DNA backbone |
sugar-phosphate-sugar-phosphate |
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What gives the DNA strand chemical polarity |
The way nucleotide subunits are linked together. One end of the strand is 3' hydroxyl the other 5' phosphate. The polarity is indicated by referring to the end of the strands this way |
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Discuss base pariring in DNA |
Known as the purine and pyrimidine combo. The complimentary base pairing enables the base pairs to be packed in the energetically most favorable arrangement in the interior of the double helix. |
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What is meant by the DNA double helix has opposite polarities? |
They run antiparallel to each other. 10 bp per turn and also have a major and minor groove. |
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The complex task of of packaging DNA is accomplished by? |
Specialized proteins that bind to and fold the DNA. generating a series of coils and loops that provide increasingly higher levels of organization and prevent DNA from becoming tangled. DNA becomes compacted in a way that allows it to reamin assecible to all of the enzymes and other proteins that replicate it, repair it, and control the expression of its genes |
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Describe a chromosome |
Each chromosome consists of a single, long, linear DNA molecule associated with proteins that fold and pack the fine thread of DNA into a compact structure. Called Chromatin. |
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Chromosomes are also associated with many other proteins involved in? |
DNA replication, repair, and gene expression |
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Human cells contains 2 copies of each chromosome? |
One inherited from your mother and father. The maternal and paternal chromosome known as homologous chromosomes. The only nonhomologous chromosome pairs are the sex chromosomes in males from y and x chromosome. |
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Define karyotype |
An ordered display of the full set of 46 human chromosomes |
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What is the most important function of chromosomes? |
To carry genes the functional unit of heredity |
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Most of the RNA molecules coded by gens are used for? |
To produce a protein |
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What is the genome made up of? |
The total genetic information carried by all the chromosomes in a cell or organism |
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Define Junk DNA
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Extra DNA large excess of interspersed DNA. Acts as a spacer material may be crucial for the long-term evolution of the species and for the proper activity of the genes. |
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Describe Interphase? |
When chromosomes are duplicated |
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Describe Mitosis |
When chromosomes are distributed or segregated to the 2 daughter nuclei. |
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What happens during interphase |
The chromosomes are extended as long, thin, tangled threads of DNA in the nucleus and cannot be easily distinguished. |
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What are the chromosomes in interphase known as? |
In thier extended state known as interphase chromosomes |
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What is the replication origin |
Nucleotide sequence where replication of the DNA begins |
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Describe the telomeres at the ends of the chromosome? |
Contain repeated nucleotide sequences that are required for the ends of chromosomes to be replicated. Also, cap the ends of the DNA molecule, preventing them from being mistaken by the cell as broken DNA that needs repair. |
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Describe the centromere |
Allows ducplicated chromosomes to be seperated during M phase. During this stage of the cell cycle the DNA coils up , adopting a more and more compact structure ultimaterely forming highly compacted/condensed mitotic chromosomes |
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Why do each chromosome tends to occupy a particular region of the interphase nucleus/ |
So different chromosomes do not become entangled with one another. Some chromosomes are attatched to particular sites on the nuclear envelope, nuclear lamina |
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What is the nucleolus |
Where the parts of the different chromosomes carrying genes that encode ribosomal RNAs cluster together |
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Histones and non histones chromosomal proteins are general classes of ? |
proteins that bind to DNA to form eukaryotic chromosomes |
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The complex of both classes of protein with nuclear DNA |
chromatin |
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Histones are responsible for the first and most fundamental level of |
chromatin packaging into the nucleosome |
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The nucleosome consist of |
Bead on the DNA when viewed. A nucleosome core particle consists of DNA wound aroung a core of proteins formed from histones. |
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Describe the histones that make up the histone octamer |
Relatively small proteins, with a high proportion of positivelly charged amino acids. The positive charges help the histones bind tightly to the negatively charged sugar-phosphate backbone of DNA. These numerous electrostatic interactions explain in part why DNA of virtually any sequence can bind to a histone octamer. |
