Chapter 1: Carbohydrates, Lipids, and Proteins Flashcards

Vocabulary flashcards covering key concepts, classifications, structures, and metabolic processes of carbohydrates, lipids, and proteins based on Chapter 1 notes.

Monosaccharides

The basic units of carbohydrates, consisting of 6 carbon, 12 hydrogen, and 6 oxygen atoms ($C_6H_{12}O_6$), including glucose, fructose, and galactose.

Disaccharides

Carbohydrates formed when 2 to 10 monosaccharides bond together, such as sucrose, lactose, and maltose.

Polysaccharides

Complex carbohydrates composed of three to thousands of monosaccharides, such as starch and fiber.

Fructose

Also known as fruit sugar or levulose, a monosaccharide found in fruit and honey with the chemical formula $C_6H_{12}O_6$, primarily metabolized in the liver for glycogen and triacylglycerol synthesis.

Galactose

A monosaccharide that combines with glucose in the mammary glands of lactating animals to form lactose.

Sucrose

A disaccharide composed of glucose and fructose (table sugar), found in beet and cane sugar, brown sugar, sorghum, maple syrup, and honey.

Lactose

A disaccharide composed of glucose and galactose (milk sugar), found exclusively in milk and milk products.

Maltose

A disaccharide composed of two glucose molecules (malt sugar), found in breakfast cereals, beer, and germinating seeds.

Starch

The storage form of carbohydrate in plants, existing as amylose and amylopectin.

Fiber

A nonstarch structural polysaccharide occurring exclusively in plants that resists breakdown by human digestive enzymes.

Glucogenesis

The process of glycogen synthesis from glucose.

Gluconeogenesis

The synthesis of glucose largely from structural components of noncarbohydrate nutrients, such as protein.

Glycogenolysis

The process of glucose formation from glycogen.

Triacylglycerols

The major storage form of fat in adipocytes (fat cells), composed of one glycerol backbone and three fatty acid chains; also known as triglycerides.

Saturated Fatty Acids

Fatty acids where carbon binds to the maximum number of hydrogens with no double bonds, found primarily in animal products and select plant oils.

Monounsaturated Fatty Acids

Unsaturated fatty acids containing exactly one double bond, found in foods such as olive oil, almond oil, and avocados.

Polyunsaturated Fatty Acids

Unsaturated fatty acids containing two or more double bonds, found in soybean oil, corn oil, and omega-3 oil.

Lipolysis

The breakdown of triacylglycerols, regulated by hormone-sensitive lipase (HSL).

Trans-Fatty Acids

Lipids derived from the partial hydrogenation of unsaturated oils that raise low-density lipoprotein (LDL) cholesterol and lower high-density lipoprotein (HDL) cholesterol.

Phospholipids

Compound lipids consisting of a fatty acid joined to a phosphate group and a nitrogen-containing molecule, essential for modulating fluid movement across cell membranes and maintaining structural integrity.

High-Density Lipoprotein (HDL)

Known as 'good' cholesterol, a lipoprotein that removes cholesterol from arterial walls.

Low-Density Lipoprotein (LDL)

Known as 'bad' cholesterol, a lipoprotein that binds to arterial walls.

Very Low-Density Lipoprotein (VLDL)

A lipoprotein that transports triacylglycerols (TAGs) to muscle and adipose tissue.

Chylomicrons

Lipoproteins that transport fat-soluble vitamins (A, D, E, and K) and are metabolized by the liver for storage in adipose tissue.

Cholesterol

A derived lipid found only in animal sources, synthesized up to 70% by the liver, which serves as a building block for plasma membranes and a precursor for vitamin D and sex hormones.

Essential Amino Acids

The eight amino acids (isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine) that the body cannot synthesize and must obtain from food.

Nonessential Amino Acids

Amino acids that the body can synthesize from other compounds at a rate sufficient to meet growth and tissue repair needs.

Complete Proteins

Proteins existing in foods that contain all essential amino acids in the quantity and correct ratio needed to maintain nitrogen balance.

Incomplete Proteins

Proteins that lack one or more essential amino acids.

Vegan

A dietary pattern that consumes only plant sources of food, excluding eggs and dairy.

Ovolactovegetarian

A plant-based dietary pattern that includes plant food sources along with dairy and eggs.

Deamination

The process of nitrogen removal from amino acids prior to breakdown, which forms urea for elimination in urine.

Transamination

The metabolic process in which an amine group from a donor amino acid transfers to an acceptor acid to form a new amino acid.

Positive Nitrogen Balance

A state where nitrogen intake from food exceeds nitrogen excretion in urine, feces, and sweat, allowing the synthesis of new tissue.

Negative Nitrogen Balance

A state where nitrogen intake is less than nitrogen excretion, causing protein to be used as energy fuel and leading to lean tissue loss.

Alanine-Glucose Cycle

A cycle in which alanine enters the blood and is converted by the liver into glucose and urea to maintain blood glucose for the nervous system and active muscles.