All cells contain genetic information encoded in a spiral-ladder shaped molecule called DNA. Plants and animals are eukaryotes, meaning their DNA is stored in a structure inside the cell called the nucleus.
DNA consists of two sugar-phosphate backbones with bases attached to each. The bases form hydrogen bonds with each other across the center of the helix. There are four bases found in DNA--adenine, thymine, guanine and cytosine, often abbreviated as A, T, C and G. Different combinations of bases code for different amino acids found in proteins. Sections of the genome that contain encoded instructions for making a particular protein are called a gene.
DNA in plant cells is stored in the nucleus, a large structure inside the cell. The nucleus is enveloped by a double membrane with holes called nuclear pores. The nuclear pores are formed by complexes of proteins that regulate traffic through the pore to control entry and exit of other molecules.
Genes in plant cells are transcribed into RNA copies called messenger RNAs or mRNAs. mRNAs are similar to DNA but exhibit several key differences; they are single-stranded, their sugar-phosphate backbone contains the five-carbon sugar ribose instead of deoxyribose and they contain the base uracil instead of thymine. mRNAs are modified then exported through the nuclear pores to go out into the cell, where complex structures called ribosomes will catalyze synthesis of proteins using the instructions encoded in the mRNA.
- "Biology"; Neil A. Campbell, Jane B. Reece, Lisa A. Urry, Michael L. Cain, Peter V. Minorsky, Steven A. Wasserman, Robert B. Jackson; 2008
About the Author
Based in San Diego, John Brennan has been writing about science and the environment since 2006. His articles have appeared in "Plenty," "San Diego Reader," "Santa Barbara Independent" and "East Bay Monthly." Brennan holds a Bachelor of Science in biology from the University of California, San Diego.