Biology concepts and applications

¶ … properties of a Carbon atom that make it ideally suited to produce varied carbon skeletons?

Besides water, carbon molecules are the most significant contributors to life. The structural and functional diversity of organic molecules emerges from the ability of carbon to form large, complex and diverse molecules by bonding to itself and to other elements such as hydrogen, oxygen, nitrogen and sulfur. Carbon atoms are the most versatile building blocks of molecules. Each one has an atomic number of 6; therefore, it has 4 valence electrons. This means that these electron completes its outer energy shell by sharing valence electrons in four covalent bonds and are not likely to form ionic bonds. Covalent bonds link carbon atoms together in long chains that form the skeletal framework for organic molecules.

Discuss what would happen if no water was present during degradation of a bio-molecule.

Since bio-molecules are complex they are made up of simpler components that have their own unique characteristics. Water is also a good solvent due to its polarity. The solvent properties of water are vital in biology, because many biochemical reactions take place only within aqueous solutions (e.g., reactions in the cytoplasm and blood). In general, ionic and polar substances such as acids, alcohols, and salts are easily soluble in water, and nonpolar substances such as fats and oils are not. Non-polar molecules stay together in water because it is energetically more favorable for the water molecules to hydrogen bond to each other than to engage in van der Waals interactions with nonpolar molecules.

-Discuss the four possible levels of protein structure and relate each level to particular bonding patterns.

There are four levels of protein structure: primary, secondary, tertiary, and quaternary. These levels also reflect their temporal sequence. Proteins are synthesized as a primary sequence and then fold into secondary then tertiary and then quaternary structures. The linear sequence of amino acids constitutes a protein's primary structure. Secondary structures arise from non-covalent interactions between amino acids across the chain. Tertiary structure is subdivided into certain portions that are termed motifs and domains. Two or more polypeptide chains may bind to each other to form a quaternary structure.

-Describe the basic characteristics of cancer cells?

Cancer cells can be deadly and harmful to all the living things they come into contact with. Cancer cells lose the ability to communicate with other cells through chemical signals. They also lose sensitivity to anti-growth signals from surrounding cells. These signals normally restrict cellular growth. Cancer cells do not have a fixed lifespan. As long as they are able get the nutrients needed to survive, cancer cells are essentially immortal. They will continue to live and divide at an uncontrolled pace unless something happens to stop them. Malignant cells that cause cancer all have the ability to evade the body's cancer surveillance system as well.

-Evaluate why meiosis and sexual reproduction are important in responding to the changing environment?

In meiosis, variation occurs, because each gamete (either sperm or egg) contains a mixture of genes from two different parent chromosomes in sexual reproduction. In other words, the genetic coupling of non-identical DNA takes place in meiosis. It results in an offspring, which has the genetic material of two different individuals. A new combination of genetic information is produced in the gametes. Therefore, in meiosis, the characteristics of parent chromosomes are combined with the characteristics of offspring chromosomes, which ultimately results in a new and unique set of chromosomes. These chromosomes contain the basic DNA chain, which determines the physical and genetic characteristics of the child.