Chapter 1_Overview Of Genetics Flashcards
Define “genome”
The DNA found within all our chromosomes
DNA, the molecule of life, contains trillions of cells. Each cell contains:
- 46 chromosomes, found in 23 pairs
- 2 meters of DNA
- Approximately 3 billion DNA base pairs per set of chromosomes, containing the bases A, T, G, and C
- Approx 20,000 to 25,000 genes coding for proteins that perform most life functions
What are some examples of controversial genetic technologies?
- DNA fingerprinting, a molecular method to identify an individual based on a DNA sample
- Mammalian cloning, which could allow for homogeneous herds
- Modifying traits in animals and plants
Define “Genetics”
- The branch of biology that deals with heredity and variation
- It stands as the unifying discipline in biology by allowing us to understand how life can exist at all levels of complexity
Define “genes”
- At the molecular level, a gene is a segment of DNA that produces a functional product
What is the functional product of most genes?
Polypeptide, a linear sequence of amino acids that folds into units that constitute proteins
What is another name for genes?
They are commonly described as traits, which are characteristics of an organism (eye color, hair texture, and height)
The chemical properties of organic molecules are essential for cell vitality in two key ways:
- The breaking of chemical bonds during the degradation of small molecules provides energy to drive cellular processes
- A second imporant function is their role as the bulding blocks for the synthesis of larger molecules
Four important categories of larger cellular molecules. Three of them form what?
- Nucleic acids (i.e., DNA and RNA)
- Proteins
- Carbohydrates
- Lipids
- The first three form macromolecules that are composed of many repeating units of smaller building blocks
What is the largest macromolecule in living cells?
DNA. A single DNA molecule can be composed of a linear sequence of hundreds of millions of nucleotides!
The formation of cellular structures relies on…
…the interactions of molecules and macromolecules
The characteristics of a cell depend on…
…the types of proteins that it makes
What is a proteome?
- All of the proteins that a cell makes at a given time
- Proteins are the workhorses of all living cells
What are some of the functions of proteins?
- Some proteins help determine the shape and structure of a given cell
- Others are inserted into cell membranes and aid in the transport of ions and small molecules across the membrane
- They also function as biological motors
- Within multicellular organisms, certain proteins also function in cell to cell recognition and signaling
Define “Enzymes”
Accelerate chemical reactions. They are a particularly important category of proteins.
Catabolic vs. Anabolic Enzymes
- Catabolic enzymes breakdown molecules or macromolecules into smaller units
- Anabolic enzymes (and accessory proteins) function in the synthesis of molecules and macromolecules throughout the cell
Define “DNA”
- (Deoxyribonucleic Acid) is what the genetic material of living organisms is made of. It stores the info needed for the synthesis of all cellular proteins.
- Basically, the main function of the genetic blueprint is to code for the production of cellular proteins in the correct cell, at the proper time, in suitable amounts
DNA is composed of…
…a linear sequence of nucleotides. Each nucleotides contains one of four nitrogen containing bases: adenine (A), thymine (T), cytosine (C), or guanine (G)
Explain how the genetic code works.
- In the code, a 3 base sequence specifies one particular amino acid among the 20 possible chocies
- One or more polypeptides form a functional protein
Define “Gene Expression”
The process of using a gene sequence to affect the characteristics of cells and organisms