biological molecules

Flashcards about carbohydrates, lipids, cell division, and DNA replication.

What are monosaccharides?

Monomers that form carbohydrates.

What are isomers?

Molecules with the same molecular formula but different arrangements of atoms.

What is a condensation reaction?

A reaction where monomers join together, forming a covalent bond and releasing water.

What is a disaccharide?

Sugar formed when two monosaccharides join together.

What is a hydrolysis reaction?

A reaction where large biological molecules are broken down by breaking a glycosidic bond, adding water.

What is a glycosidic bond?

A bond formed between monosaccharides.

What are polysaccharides?

Many monomers joined together.

What is cellulose?

Found in plant cell walls, provides rigidity; composed of beta glucose with beta 1-4 glycosidic bonds.

What is osmosis?

Diffusion of water from a dilute to a concentrated solution through a partially permeable membrane.

What is starch?

Storage molecule of glucose found in plants; contains alpha glucose with 1,4 and 1,6 linkages.

What is glycogen?

Storage molecule of glucose found in animals; highly branched for quick hydrolysis.

What is the Benedict test?

Test for reducing sugars; positive result indicated by color change from blue to orange/brown.

What is the iodine test?

Test for starch; positive result indicated by a blue-black color.

What is a fatty acid?

Made of long chains of carbon with hydrogens attached, and a carboxyl group.

What is ester bond formation?

Reaction forming an ester bond between a fatty acid and glycerol, releasing water.

What is a saturated fatty acid?

Fatty acid with no double bonds between carbon atoms; saturated with hydrogen.

What is an unsaturated fatty acid?

Fatty acid with one or more double bonds between carbon atoms.

What are triglycerides?

Consist of glycerol and three fatty acids; functions include energy storage and water source.

What are phospholipids?

Molecule with a polar, hydrophilic head and two nonpolar, hydrophobic tails; forms bilayers in cell membranes.

What is the emulsion test?

A test used to detect the presence of lipids forming a milky white emulsion.

What is ATP?

Adenosine triphosphate; a molecule composed of adenine, ribose, and three phosphate groups.

What is ATP synthase?

Enzymes that catalyze the synthesis of ATP from ADP and inorganic phosphate.

What is ATP hydrolase?

Enzymes that catalyze the hydrolysis of ATP to ADP and inorganic phosphate, releasing energy.

What is a catalyst?

A substance that speeds up the rate of a chemical reaction without being permanently changed.

What is activation energy?

The minimum amount of energy required for a reaction to proceed.

What is the active site?

The specific region of an enzyme where the substrate binds and catalysis occurs.

What is the induced fit model?

Model describing how the active site of an enzyme changes shape to better fit the substrate.

What are inhibitors?

Substances that reduce the activity of enzymes.

What are competitive inhibitors?

Inhibitors that bind to the active site of an enzyme, preventing substrate binding.

What are non-competitive inhibitors?

Inhibitors that bind to a site on the enzyme other than the active site, changing the shape of the active site.

What is pH?

A measure of the concentration of H+ ions in a solution.

What is a nucleotide?

Building block of DNA, consisting of a phosphate group, pentose sugar, and nitrogenous base.

What is a phosphodiester bond?

Bond formed between nucleotides in DNA.

What is DNA?

Molecule that carries genetic information; double helix structure with sugar-phosphate backbone and complementary base pairs.

What are complementary base pairs?

Having the same percentage of adenine and thymine, and guanine and cytosine.

What are exons?

DNA in eukaryotes contains these coding regions.

What are introns?

Non-coding regions found in eukaryotic DNA.

What does it mean that DNA replication is semi-conservative?

DNA replicates in this manner. Result is two stands of DNA: one old, one new.

What are histones?

Protein molecules around which DNA is tightly coiled to form chromatin.

What is binary fission?

The process through which prokaryotic cells divide.

What is cell division?

The process by which multicellular organisms grow from tiny bundles of cells to full sized adults.

What is cytokinesis?

The division of the cytoplasm.

What happens during interphase?

Cell grows, makes copies of all its DNA and organelles.

What is mitosis?

The nucleus divides into 2 during this process.

Prophase

Chromatin condenses into chromosomes; nuclear envelope breaks down.