Biology 110: The Molecules of Cells Flashcards

A set of 50 flashcards based on the lecture notes for Chapter 3: The Molecules of Cells, covering organic compounds, carbohydrates, lipids, proteins, and nucleic acids.

What are carbon-containing compounds that serve as the chemical building blocks of life called?

Organic compounds

Which group of biological molecules serve as a cell's fuel and building material?

Carbohydrates

Which group of biological molecules are hydrophobic and have diverse functions like energy storage and membrane structure?

Lipids

Which molecules are essential to the structures and functions of life and are made of amino acid polymers?

Proteins

Which molecules store, transmit, and help express hereditary information?

Nucleic acids

What is the name of the enzyme that breaks down the milk sugar lactose?

Lactase

How many valence electrons does carbon have, allowing it to bond with four other atoms?

$$4$$

What is the molecular shape of methane ($CH_4$), which is formed by four single bonds?

Tetrahedral shape

What are compounds composed only of carbon and hydrogen atoms called?

Hydrocarbons

What term refers to molecules with the same molecular formula but different structures and properties?

Isomers

Provide an example of a pair of isomers mentioned in the lecture.

Butane and isobutane

What is the name of the chemical group consisting of a hydrogen atom bonded to an oxygen atom ($-OH$)?

Hydroxyl group

Which chemical group consists of a carbon atom double bonded to an oxygen atom ($C=O$)?

Carbonyl group

What is the name of the chemical group with the formula $-COOH$, consisting of a carbon double bonded to an oxygen and a hydroxyl group?

Carboxyl group

Which chemical group contains a nitrogen bonded to two hydrogens ($-NH_2$)?

Amino group

What chemical group is characterized by a phosphorus atom bonded to four oxygen atoms ($-OPO_3^{2-}$)?

Phosphate group

What is the chemical formula for a methyl group?

$$-CH_3$$

Which of the major chemical groups is nonpolar and not reactive?

Methyl group

What two sex hormones are used to illustrate how small differences in chemical groups affect function?

Testosterone and Estradiol

What are very large molecules, such as proteins or DNA, called?

Macromolecules

What are polymers made of?

Strings of smaller building blocks called monomers

What is the name of the protein found in sweat mentioned as an example of a macromolecule?

Dermcidin

By what reaction are monomers linked to form polymers through the removal of water?

Dehydration reaction

What reaction is used to break polymers apart by adding water?

Hydrolysis

What are the specialized macromolecules that speed up chemical reactions, such as dehydration and hydrolysis?

Enzymes

What are the monomers of carbohydrates, typically having formulas that are multiples of $CH_2O$?

Monosaccharides

What are two examples of common monosaccharides mentioned in the text?

Glucose and fructose

What shape do most 5 and 6-carbon sugars form in aqueous solutions?

Rings

What is formed when two monosaccharides are joined through a dehydration reaction?

Disaccharide

What is the most common disaccharide, specifically mentioned as the common sugar found in kitchens?

Sucrose

The FDA recommends that no more than what percentage of daily calories come from added sugar?

$$10\%$$

What are carbohydrate molecules composed of 100s to 1000s of monosaccharides linked together called?

Polysaccharides

What are two examples of storage polysaccharides found in plants and animals?

Starch and glycogen

Which structural polysaccharide is a major component of plant cell walls?

Cellulose

Which structural polysaccharide is found in the cell walls of fungi and the exoskeletons of insects and crustaceans?

Chitin

What is the defining trait shared by all lipids?

They are hydrophobic (water-fearing)

What are the components of a fat, also known as a triglyceride?

Glycerol linked to three fatty acids

What type of fatty acids contain one or more double bonds and are typical of plant oils?

Unsaturated fatty acids

Which type of fats have the maximum number of hydrogens and are solid at room temperature?

Saturated fatty acids

What harmful byproduct is created during the process of adding hydrogen atoms to unsaturated fats?

Trans fats

What are the major lipid components of cell membranes?

Phospholipids

Which steroid is a common component in animal cell membranes and a precursor for making sex hormones?

Cholesterol

How many different amino acid monomers are used to build proteins?

$$20$$

What happens during the process of denaturation?

A protein unravels, loses its specific shape, and loses its function

What are the three core parts of the generic structure of an amino acid?

An amino group, a carboxyl group, and an R group

What is the specific name for the bond that joins the carboxyl group of one amino acid to the amino group of the next?

Peptide bond

Which level of protein structure describes the specific sequence of amino acids in a polypeptide chain?

Primary structure

What stabilizes the secondary structure of a protein, such as an alpha helix or beta pleated sheet?

Hydrogen bonds

What refers to the overall three-dimensional shape of a polypeptide resulting from R group interactions?

Tertiary structure

What are the three components that make up a nucleotide monomer?

A sugar, a phosphate group, and a nitrogenous base