Biology Unit 2: Molecules and Membranes

Molecules found in cell membranes, containing a hydrophobic tail (fatty acids) and a hydrophilic head (carbohydrates).

A sterol with a four-ring structure, amphipathic due to a hydroxyl group.

Polymers of nucleotides, serving as the primary carriers of genetic information in cells.

A type of nucleic acid that stores and transmits genetic information.

A type of nucleic acid involved in protein synthesis.

The building blocks of nucleic acids, composed of a nitrogenous base, a sugar, and a phosphate group.

A special bond that links nucleotides together in a nucleic acid chain.

The sequence of bases in a polynucleotide chain that determines its function.

A carbohydrate monomer, the basic building block for more complex carbohydrates. Its formula is (CH2O)n, where n is the number of carbon atoms.

Glucose, a 6-carbon monosaccharide, is the primary energy source for cells.

Sugars with 5 or more carbons can form ring structures, which are the most common form within cells.

A process where two monosaccharides are linked by removing a water molecule and forming a glycosidic bond.

A polymer made up of a few monosaccharides linked together.

A polymer composed of hundreds or thousands of monosaccharides linked together by glycosidic bonds.

The most common polysaccharide in animals, used for storing energy. It's mainly made up of glucose molecules.

A polysaccharide found in plants, used for storing energy. It's mainly made up of glucose molecules.

A type of lipid that is the main component of cell membranes. They consist of two fatty acid molecules attached to a glycerol molecule and a phosphate group. The phosphate group can also bind to another polar molecule like phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, or phosphatidylinositol.

A type of lipid found in cell membranes; the only non-glyceric phospholipid. Instead of glycerol, these have serine as part of their polar head group, with two fatty acid chains attached.

The simplest lipids, composed of long hydrocarbon chains (16-18 carbons) with a carboxyl group at the end. These are the building blocks of many other lipids.

Lipids that consist of three fatty acid molecules linked to a glycerol molecule. They serve as energy storage molecules for cells.

Lipids that are important for cell signaling, acting as molecular messengers carrying signals from receptors to targets within cells. Examples include steroid hormones like estrogen and testosterone.

Amphipathic molecules are molecules that have both hydrophobic and hydrophilic regions. This property allows them to interact with both water and oil.

The sequence of amino acids in a polypeptide chain.

Regular, repeating arrangement of amino acids within localized regions of the polypeptide chain.

The overall three-dimensional folding of a polypeptide chain, determined by interactions between amino acid side chains.

The arrangement of multiple polypeptide chains in a protein complex.

This property allows individual lipids and proteins within the membrane to move laterally.

They maintain the fluidity of the membrane by weakening interactions between longer fatty acid chains.

This structure is essential for separating the cell's interior from the environment and defining internal compartments in eukaryotic cells.

A molecule that serves as the main form of chemical energy in cells, primarily used for energy transfer during cellular processes.

A type of nucleotide that plays a crucial role in cellular signaling pathways, acting as a second messenger.

Macromolecules that are responsible for carrying out the tasks defined by the information contained in nucleic acids. They are incredibly diverse and perform a wide range of functions in cells.

The building blocks of proteins. There are 20 different amino acids, each with a unique side chain (R-group) that defines its chemical properties.

A type of bond that connects amino acids in a protein chain. It is formed between the carboxyl group of one amino acid and the amino group of the next.

A linear chain of amino acids linked together by peptide bonds. It is a fundamental unit of protein structure.

The specific sequence of amino acids in a polypeptide chain. It determines the protein's three-dimensional structure and ultimately its function.

The three-dimensional shape of a protein that is determined by its amino acid sequence and interactions between amino acids. It is crucial for the protein's function.

A molecule that inserts into the lipid bilayer, with its polar hydroxyl group near the hydrophilic head of phospholipids, and its hydrocarbon rings interact with the hydrophobic chains of fatty acids of phospholipids.

Proteins embedded in the lipid bilayer, some spanning the entire membrane (transmembrane proteins).

A common structure in integral membrane proteins, formed by folding beta sheets into a barrel-like shape.

Proteins indirectly associated with the membrane, usually through interactions with other proteins. They are amphipathic molecules.

The ability of a membrane to allow certain substances to pass through while blocking others.

Transmembrane proteins that create pores in the membrane, allowing the passage of specific molecules based on size and charge.

Protein channels that allow the passage of inorganic ions, such as sodium, potassium, calcium, and chloride.

The movement of molecules across a membrane from an area of high concentration to an area of low concentration, without requiring energy.