{"id":159,"date":"2009-12-13T03:25:28","date_gmt":"2009-12-12T14:25:28","guid":{"rendered":"http:\/\/science4all.blogtown.co.nz\/?p=159"},"modified":"2009-12-22T22:31:31","modified_gmt":"2009-12-22T09:31:31","slug":"dna-and-gene-expression","status":"publish","type":"post","link":"https:\/\/science4all.blogtown.co.nz\/?p=159","title":{"rendered":"DNA and Gene Expression"},"content":{"rendered":"<p><strong>Function of chromosomes<\/strong><\/p>\n<p>When a cell is not dividing, its chromosomes become very long and thin. Along the length of chromosome is a series of chemical structures called genes. The chemical which forms the genes is called DNA. Each gene controls some part of the chemistry of the cell. It is these genes which provide the instructions. One gene may instruct the cell to make the pigment which is formed in the iris of brown eyes. On one chromosome there will be a gene which causes the cells of the stomach to make the enzyme pepsin. When the chromatids separate at mitosis, each cell will receive a full set of genes. In this way, the chemical instructions in the zygote are passed on to all cells of the body. All the chromosomes, all the instructions are faithfully reproduced by mitosis and passed on complete to all the cells.<\/p>\n<p style=\"text-align: center\">&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p style=\"text-align: left\">&#8216;Chromosome&#8217;\uacfc &#8216;DNA&#8217;\uc758 \uc758\ubbf8\ub97c \uc81c\ub300\ub85c \uc54c\uace0 \uc0ac\uc6a9\ud574\uc57c\ud55c\ub2e4. Chromosome\uc774\ub780 \uc138\ud3ec\uc758 \ud575\uc548\uc5d0 \uc788\ub294 \uc720\uc804\ubb3c\uc9c8(genetic material)\uc744 \ub9d0\ud55c\ub2e4. DNA\ub294 Deoxyribonucleic Acid\uc758 \uc57d\uc790\uc778\ub370&#8230; \uc774\uac83\uc744 \uc0dd\uac01\ud574\ubcf4\uba74 \ubd84\uba85 \ud654\ud559\uc801 \uc758\ubbf8\ub97c \uac00\uc9c0\uace0 \uc788\ub2e4\ub294\uac78 \uc54c\uac8c\ub41c\ub2e4. DNA\ub294 \uc989, chromosome\uc744 \uc774\ub8e8\uace0 \uc788\ub294 molecule\uc758 \uc9d1\ud569\uc774\uace0, nucleic acid\/nucleotide \ub85c \uc774\ub8e8\uc5b4\uc838 \uc788\ub2e4.<\/p>\n<p style=\"text-align: left\">(NCEA\uc2dc\ud5d8\uc774\ub4e0 CIE\uc2dc\ud5d8\uc774\ub4e0 \uc774 \ub450\ub2e8\uc5b4\ub97c \uc81c\ub300\ub85c \uad6c\ubd84\ud558\uc9c0 \ubabb\ud558\uace0 \uc4f0\uc9c0 \ubabb\ud558\uba74 \uc810\uc218\ub97c \ud68d\ub4dd\ud560\uc218 \uc5c6\ub2e4!)<\/p>\n<p style=\"text-align: center\">&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p><strong>Genes<\/strong><\/p>\n<p>Chromosomes consist of a protein framework, with a long DNA molecule coiled round the framework in a complicated way. Its the DNA part of the chromosome which controls the inherited characters and it is sections of the DNA molecule which constitute the genes.\u00a0The gene which causes brown eyes will have no effect in a stomach cell and the gene for making pepsin will not function in the cells of the eye.<\/p>\n<p style=\"text-align: center\">\n<p style=\"text-align: center\">&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p>(\ub2e4\uc2dc DNA\ub85c \ub3cc\uc544\uc640\uc11c..!)<\/p>\n<p>A\u00a0<strong>DNA molecule <\/strong>is a long chain of nucleotides. \u00a0A nucleotide is a 5 carbon sugar molecule joined to a phosphate group and an organic base.<\/p>\n<p>In DNA, the sugar is\u00a0<strong>Deoxyribose<\/strong> and the organic base is either<\/p>\n<ul>\n<li>A = adenine<\/li>\n<li>T = thymine<\/li>\n<li>C = cytosine<\/li>\n<li>G = Guanine<\/li>\n<\/ul>\n<p>The sequence of bases forms a code which instructs the cell to make particular proteins. Proteins are made from amino acids linked together. The type and sequence of the amino acids joined together will determine the kind of protein formed. It is the sequence of bases in the DNA molecule which decides which amino acids are used and in which order they are joined. Each group of three bases stands for one amino acid.<\/p>\n<p>A gene, then, is a sequence of triplets of the four bases, which specifies an entire protein. Most proteins contain a thousand or more bases.<\/p>\n<p>The chemical reaction which take place in a cell determine what sort of a cell it is and what its functions are. These chemical reactions are controlled by enzymes. Enzymes are proteins. Therefore the genetic code of DNA, in determining which proteins, particularly enzymes are produced in a cell, and determines the structure and function of the enzymes.<\/p>\n<p style=\"text-align: center\">&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p><strong>Replication of DNA<\/strong><\/p>\n<p>(\uae30\uc5b5\ud560\uac83! Replication\uc740 Mitosis \uacfc\uc815\uc911 \uc77c\uc5b4\ub09c\ub2e4.)<\/p>\n<p>The DNA in a chromosome consists of 2 chains of nucleotides held together by chemical bonds between the bases. The size of the molecule ensures that adenine always pairs with thymine and cytosine pairs with guanine. The double strand is twisted to form a helix.<\/p>\n<p>Before cell division can occur, the DNA of the chromosome has to replicate \u2013 to make identical copy of it-self. To do this, enzymes make the double strands of DNA unwind and separate into two single strands rather like undoing a zip.<\/p>\n<p>Nucleotides are brought to the unzipped DNA and joined to the exposed bases with the aid of enzymes. The adenine of an arriving nucleotide always joins to the thymine of the DNA, and cytosine to the guanine.<\/p>\n<p>The new nucleotides join up to form a chain attached to the exposed strand. This happens all the way along each DNA strand. Since this is happening in both strands of DNA strand, the double helix is replicated and the full set of genetic instructions is passed to both daughter cells at cell division.<\/p>\n<p style=\"text-align: center\">&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p style=\"text-align: left\">\uc218\ub9ce\uc740 \uad81\uad7c\uc99d\uc744 \ud574\uc18c\ud574\uc57c\ub9cc \uc774\ud574\ud560\uc218 \uc788\ub294 Gene expression! \uacf5\ubd80\ud558\uba74 \ud560\uc218\ub85d \uc5b4\ub824\uc6b4 \ubd80\ubd84\uc774\uae34 \ud558\uc9c0\ub9cc \uacb0\ucf54 \ub118\uc9c0 \ubabb\ud560 \uc0b0\uc740 \uc544\ub2c8\ub2e4. <img src=\"https:\/\/science4all.blogtown.co.nz\/wp-content\/plugins\/classic-smilies\/img\/icon_smile.gif\" alt=\":)\" class=\"wp-smiley\" style=\"height: 1em; max-height: 1em;\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Function of chromosomes When a cell is not dividing, its chromosomes become very long and thin. Along the length of chromosome is a series of chemical structures called genes. The chemical which forms the genes is called DNA. Each gene controls some part of the chemistry of the cell. It is these genes which provide &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/science4all.blogtown.co.nz\/?p=159\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;DNA and Gene Expression&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1509,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"slim_seo":{"title":"DNA and Gene Expression - science4all","description":"Function of chromosomes When a cell is not dividing, its chromosomes become very long and thin. Along the length of chromosome is a series of chemical structure"},"footnotes":""},"categories":[6302,6421,1],"tags":[],"class_list":["post-159","post","type-post","status-publish","format-standard","hentry","category-year12-biology","category-year12-science","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=\/wp\/v2\/posts\/159","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=\/wp\/v2\/users\/1509"}],"replies":[{"embeddable":true,"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=159"}],"version-history":[{"count":2,"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=\/wp\/v2\/posts\/159\/revisions"}],"predecessor-version":[{"id":354,"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=\/wp\/v2\/posts\/159\/revisions\/354"}],"wp:attachment":[{"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=159"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=159"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/science4all.blogtown.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=159"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}