Why is DNA described as a 'double helix'?
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Because the strands coil about each other along their length, forming a double spiral.
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Why is DNA described as a 'double helix'?
Because the strands coil about each other along their length, forming a double spiral.
What are nucleic acids responsible for?
They carry the genetic blueprint of a cell and carry instructions for the functioning of the cell.
What are DNA and RNA made up of?
Monomers known as nucleotides.
Why is carbon considered the 'foundation' element for molecules in living things?
Because carbon atoms, bonded to other carbon atoms or other elements, form the fundamental components of many molecules found in living things.
What are the two main types of nucleic acids?
Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
What is the most common disaccharide?
Sucrose, or table sugar, composed of glucose and fructose.
What is a polysaccharide?
A long chain of monosaccharides linked by covalent bonds, which may be branched or unbranched and contain different types of monosaccharides.
How are the strands of DNA formed?
With bonds between phosphate and sugar groups of adjacent nucleotides.
What are some examples of animal waxes?
Beeswax and lanolin.
What are the functions of proteins?
They may be structural, regulatory, contractile, protective, serve in transport, storage, or membranes, or be toxins or enzymes.
Where is lactose naturally found?
In milk.
What are the functions of lipids in a cell?
Energy storage, insulation, building blocks of hormones, and a constituent of the plasma membrane.
What are the monomers of lactose?
Glucose and galactose.
What is the structure of DNA?
Double-helical, composed of two strands of nucleotides.
How many electrons does carbon contain in its outer shell?
Four electrons.
What is the simplest organic carbon molecule?
Methane (CH4), in which four hydrogen atoms bind to a carbon atom.
What are hormones and what do they do?
Hormones are chemical signaling molecules, usually proteins or steroids, that act to control or regulate specific physiological processes, including growth, development, metabolism, and reproduction.
What are the three common disaccharides?
Lactose, maltose, and sucrose.
Why are lipids hydrophobic?
Because they are nonpolar molecules due to the presence of nonpolar carbon-carbon or carbon-hydrogen bonds.
What is the major constituent of the plasma membrane?
Phospholipids.
What are biological macromolecules?
Large molecules necessary for life built from smaller organic molecules.
What are waxes made up of?
A hydrocarbon chain with an alcohol (–OH) group and a fatty acid.
What are the three subtypes of carbohydrates?
Monosaccharides, Disaccharides, Polysaccharides.
How are the strands of DNA bonded to each other?
At their bases with hydrogen bonds.
What are the functions of carbohydrates in the body?
Providing energy, particularly through glucose, and other important functions in humans, animals, and plants.
What are enzymes and what do they do?
Enzymes are usually proteins that act as catalysts in biochemical reactions, such as digestion. They can break molecular bonds, rearrange bonds, or form new bonds.
How is maltose formed?
From a dehydration reaction between two glucose molecules.
What are the components of a fat molecule?
Glycerol and fatty acids.
What is the most common monosaccharide?
Glucose.
What is the structure of a fatty acid?
A long chain of hydrocarbons with an acidic carboxyl group attached.
How are disaccharides formed?
They form when two monosaccharides undergo a dehydration reaction, releasing a molecule of water and forming a covalent bond between atoms in the two sugar molecules.
What is the difference between saturated and unsaturated fatty acids?
Saturated fatty acids have only single bonds between neighboring carbons, while unsaturated fatty acids contain double bonds in the hydrocarbon chain.
What is the essential feature of a monomer?
Polyfunctionality, the capacity to form chemical bonds to at least two other monomer molecules.
What are the three components of each nucleotide?
A nitrogenous base, a pentose (five-carbon) sugar, and a phosphate group.
What is the structure of steroids?
They have a ring structure and are hydrophobic.
What is the fundamental structure of amino acids?
A central carbon atom bonded to an amino group (–NH2), a carboxyl group (–COOH), and a hydrogen atom, with a variable R group.