UNIT 1 Flashcards
(16 cards)
What is the primary role of DNA in living organisms, and what are its basic monomeric units? WHAT IS IT COMPOSED OF
AND WHAT ARE ITS BASES
The primary role of DNA (Deoxyribonucleic Acid) is to store hereditary information that can be passed from cell to cell and from parent to offspring.
DNA is made of smaller molecules called monomers, which are nucleotides!!!
Each nucleotide is composed of three parts: a sugar, a phosphate, and a base.
The four different types of bases in DNA are Adenine (A), Thymine (T), Guanine (G), and Cytosine (C).
How are nucleotides linked together to form a nucleic acid strand, and what is the term for the resulting structural feature?
Nucleotides within the same strand of DNA or RNA are connected through covalent bonds, forming a strong and stable ‘backbone’ known as the sugar-phosphate backbone.
Compare and contrast the key structural differences between DNA and RNA.
DNA typically has two strands, forming a double helix, while RNA typically has one strand.
DNA contains Adenine (A), Thymine (T), Cytosine (C), and Guanine (G), while RNA contains Adenine (A), Uracil (U), Cytosine (C), and Guanine (G).
DNA contains Deoxyribose sugar, while RNA contains Ribose sugar.
Explain the significance of complementary base pairing in DNA replication and gene expression.
Complementary base pairing is fundamental to DNA functions, based on hydrogen bonding between the bases. In DNA, Adenine (A) always bonds with Thymine (T), and Guanine (G) always bonds with Cytosine (C). This ensures accurate genetic information preservation during replication and enables information transfer from DNA to RNA during transcription.
APPLE - TREE
CAR - GARAGE
How does the diversity of DNA base sequences contribute to its immense capacity for storing information?
The genetic information in DNA is stored in the specific sequence of its bases (A, T, C, G). The number of possible combinations for a sequence of ‘n’ nucleotides is 4^n, allowing for immense diversity in DNA sequences and a great capacity for storing data.
What evidence from nucleic acids suggests a universal common ancestry for all life forms?
The evidence for universal common ancestry comes from the conservation of the genetic code. All living organisms and viruses use essentially the same genetic code, suggesting a common evolutionary origin.
Describe the unique chemical properties of carbon atoms that allow them to form the diverse compounds essential for life.
Carbon atoms are versatile, enabling the formation of complex molecules. Their key properties include
1. covalent bonding,
2. tetrahedral disposition,
3. ability to bond with various elements
4.capacity for chain and ring formation.
Explain the processes of condensation reactions and hydrolysis reactions in the context of biological macromolecules.
Condensation reactions join monomers to form polymers, releasing water and consuming energy. Hydrolysis reactions use water to separate monomers from polymers, typically releasing energy and being vital for processes like digestion.
Describe the general characteristics and functions of monosaccharides and polysaccharides.
Monosaccharides are simple carbohydrates, soluble in water, and used by organisms. Polysaccharides are large polymers formed from monosaccharides, generally insoluble in water, with key examples including starch, glycogen, and cellulose.
What are lipids, and what are their characteristic hydrophobic properties? Provide examples.
Lipids are organic compounds characterized by their hydrophobic properties, being insoluble in water. Examples include fats, oils, waxes, and steroids.
LESS OXYGEN TO CARBON RATIO
Differentiate between saturated, monounsaturated, and polyunsaturated fatty acids, including their impact on melting point and common sources.
Saturated fatty acids have no double bonds and higher melting points, found in fats. Monounsaturated fatty acids have one double bond, while polyunsaturated fatty acids have two or more, generally having lower melting points and found in oils.
Discuss the roles of triglycerides in adipose tissues.
Triglycerides in adipose tissues provide thermal insulation, long-term energy storage, and shock absorption, being chemically stable and releasing more energy than carbohydrates.
How do the hydrophobic and hydrophilic regions of phospholipids contribute to the formation of phospholipid bilayers?
Phospholipids are amphipathic, with hydrophilic heads and hydrophobic tails. In water, they arrange into bilayers, with tails facing inward and heads facing outward, forming the fundamental component of cell membranes.
What is the generalized structure of an amino acid, and what makes different amino acids unique?
Amino acids have a central alpha-carbon atom with an amine group, carboxyl group, hydrogen atom, and an R-group. The uniqueness of amino acids comes from their R-groups, which determine their chemical properties.
How are amino acids joined to form dipeptides and longer polypeptide chains? What catalyzes this process?
Amino acids are joined through a condensation reaction, forming peptide bond and releasing water. Depepetide formation. This process is catalyzed by ribosomes.
How do high temperature and extreme pH affect protein structure? What is the term for this effect?
High temperature and extreme pH can break weak interactions in proteins, disrupting their three-dimensional shape, a process known as denaturation, which typically results in loss of biological function.
