Midterm Exam Review: Honors Biology - January 2026

These flashcards cover key concepts from the Honors Biology midterm exam lecture notes for review.

What are the seven characteristics of living things?

1. Made up of cells 2. Based on the universal genetic code (DNA) 3. Maintain homeostasis 4. Respond to their environment 5. Obtain and use energy (metabolism) 6. Grow and develop 7. Reproduce

What is a polar covalent bond?

A bond where electrons in a covalent bond are not shared equally.

What distinguishes nonpolar molecules from polar molecules?

Nonpolar molecules have electrons that are shared equally in a covalent bond.

Why is the polar nature of water biologically significant?

Most cells and tissues contain large amounts of water; polar molecules and ions dissolve in water, facilitating movement in and between living cells.

What is a hydrogen bond?

A weak attraction between a slightly positive hydrogen atom in a polar molecule and a nearby slightly negative atom of another molecule.

How do hydrogen bonds contribute to the properties of water?

They provide an attractive force between water molecules, resulting in water being a liquid at room temperature.

What role does pH play in biological systems?

pH helps regulate chemical reactions in cells, and organisms have mechanisms to control pH and respond to changes.

Define acids and bases in terms of pH.

Acids contain H+ and release it in solution; bases contain OH- and release it in solution.

What is the pH scale range and what does it indicate?

The pH scale runs from 0 to 14, indicating the balance of H+ and OH- ions; neutral solutions have a pH of 7.

What are organic compounds?

Chemical compounds that contain carbon-hydrogen bonds.

What is dehydration synthesis?

A reaction that links monomers to form a polymer by removing H+ and OH-, producing water.

What are monosaccharides?

Simple sugars that are the basic building blocks of carbohydrates.

What is a disaccharide?

A double sugar formed from two monosaccharides through dehydration synthesis.

What distinguishes saturated fatty acids from unsaturated fatty acids?

Saturated fatty acids have all single bonds between carbon atoms, while unsaturated fatty acids contain at least one double or triple bond.

What is the function of cholesterol in the body?

Cholesterol is found in cell membranes and is a precursor for lipid-based hormones.

What are proteins made of?

Proteins are made of amino acids, which are linked by peptide bonds.

How do enzymes function in chemical reactions?

Enzymes lower the activation energy needed for reactions and act as catalysts.

What is the basic structure of nucleotides?

Nucleotides consist of a 5-carbon sugar, a phosphate group, and a nitrogen base.

Describe the structure of DNA.

DNA consists of two strands of nucleotides forming a double helix, with sugar and phosphate groups on the sides and nitrogen bases as rungs.

What are chloroplasts and their function?

Chloroplasts are organelles that conduct photosynthesis, converting light energy to chemical energy.

What is glycolysis?

The first stage of cellular respiration that breaks down glucose into pyruvic acid, producing ATP and NADH.

What happens during fermentation?

Fermentation is a process that allows glycolysis to continue producing ATP in the absence of oxygen, regenerating NAD+.

What are the end products of alcohol fermentation?

Alcohol and carbon dioxide are produced during alcohol fermentation.