Introduction to Carbohydrates and Lipids

These flashcards cover essential vocabulary related to the lecture on carbohydrates and lipids, helping students better understand their structure, function, and roles in biological systems.

Carbohydrates

Macromolecules that play a vital role in energy storage, cell structure, and cell recognition.

Monosaccharides

Single sugar molecules, also known as 'one-sugar' monomers.

Oligosaccharides

Short chains of sugar units, typically composed of a few monosaccharides.

Polysaccharides

Large polymers made up of numerous monosaccharides.

Hydrophilic

Substances that have an affinity for water; typically polar.

Carbonyl group

A functional group consisting of a carbon atom double-bonded to an oxygen atom.

Hydroxyl group

A functional group consisting of an oxygen atom bonded to a hydrogen atom.

Aldose

A monosaccharide with the carbonyl group at the end of the carbon chain.

Ketose

A monosaccharide with the carbonyl group located in the middle of the carbon chain.

Triose

A monosaccharide that contains three carbon atoms.

Pentose

A monosaccharide that contains five carbon atoms.

Hexose

A monosaccharide that contains six carbon atoms.

Disaccharide

Two monosaccharides linked together through a glycosidic linkage.

Glycosidic linkage

A covalent bond formed between two hydroxyl groups during a condensation reaction.

Hydrolysis reaction

A chemical process that breaks down a compound by adding water.

Starch

A polysaccharide used for storing energy in plants; composed of α-glucose monomers.

Glycogen

A storage polysaccharide used for energy in animals, similar in structure to starch.

Cellulose

A structural polysaccharide that forms the cell wall of plants, composed of β-glucose monomers.

Chitin

A structural polysaccharide found in fungal cell walls and exoskeletons of arthropods.

Peptidoglycan

A structural polymer found in bacterial cell walls, consisting of alternating monosaccharides.

Dietary fiber

Carbohydrates that are not easily hydrolyzed, contributing to digestive health.

Glycoproteins

Molecules made of carbohydrates attached to proteins, involved in cell signaling.

Glycolipids

Molecules made of carbohydrates attached to lipids, important for cell recognition.

Antigens

Molecules that can provoke an immune system response, often found on cell surfaces.

Photosynthesis

The process by which plants convert sunlight into chemical energy stored in carbohydrates.

Lipid

A diverse group of hydrophobic organic molecules, including fats and phospholipids.

Hydrophobic

Substances that do not have an affinity for water; typically nonpolar.

Fatty acid

A hydrocarbon chain connected to a carboxyl group, a key component of lipids.

Saturated fat

A type of fat with no double bonds between carbon atoms in its hydrocarbon chain.

Unsaturated fat

A type of fat with one or more double bonds in its hydrocarbon chain.

Triacylglycerols

Also known as triglycerides; fats composed of three fatty acids linked to glycerol.

Steroids

Lipids characterized by a four-ring structure; includes cholesterol and hormones.

Phospholipid

A lipid containing a glycerol molecule, two fatty acids, and a phosphate group.

Amphipathic

Molecules that have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts.

Phospholipid bilayer

A double layer of phospholipids that forms the basic structure of cell membranes.

Selective permeability

The property of a membrane that allows some substances to cross more easily than others.

Diffusion

The movement of molecules from an area of high concentration to an area of low concentration.

Osmosis

The diffusion of water across a selectively permeable membrane.

Hypertonic solution

A solution with a higher concentration of solutes compared to another solution.

Hypotonic solution

A solution with a lower concentration of solutes compared to another solution.

Isotonic solution

A solution with equal concentrations of solutes compared to another solution.

Fluid-mosaic model

Model describing the structure of cell membranes as a dynamic mixture of phospholipids and proteins.

Integral membrane proteins

Proteins that span the entire lipid bilayer; involved in transport and signaling.

Peripheral membrane proteins

Proteins that associate with the membrane but do not span it.

Molecular shape of saturated fatty acids

Straight chains that can tightly pack together.

Molecular shape of unsaturated fatty acids

Kinked chains that prevent tight packing due to double bonds.

Carbohydrates' role in energy storage

Store energy in the form of sugars, especially in starch and glycogen.

Carbohydrates' role in cell structure

Form cellular components like cell walls in plants and exoskeletons in arthropods.

Carbohydrates' role in signaling

Facilitate communication and identification between cells through glycoproteins and glycolipids.

Condensation reaction

A reaction where two molecules combine, resulting in the release of a water molecule.

N-acetylglucosamine (NAG)

The monomer that makes up chitin; similar to glucose.