Carbohydrates, lipids, proteins, nucleic acids
What are the four classes of large biological molecules that all living things are made up of?
Large molecules composed of thousands of covalently connected atoms
Molecular structure and function
What in a molecule are inseparable?
A long molecule consisting of many similar building blocks
Small building-block molecules
Three of the four
How many classes of life's organic molecules are polymers?
Sugar is its building block
A peptide; Amino acids are its building blocks
Fatty acids and glycerols are its building blocks
Occurs when two monomers bond together through the loss of a water molecule
Polymers are disassembled to monomers; A reaction that is essentially the reverse of the dehydration reaction
breaks down; hydrates (water is added)
What does hydrolysis do?
Builds; water is removed
What does synthesis/hydration do?
A + B --> C + H2O
Formula for synthesis
A + B <-- C + H2O
Formula for hydrolysis
Each cell has thousands of different of these
An immense variety of what can be built from a small set of monomers
Sugars and the polymers of sugars
monosaccharides, or single sugars
The simplest carbohydrates
Carbohydrate macromolecules; polymers composed of many sugar building blocks
Have molecular formulas that are usually multiples of CH2O
The most common monosaccharide
what do sugars form in aqueous solutions
Serve as a major fuel for cells and as raw material for building molecules
Ribose and Deoxyribose
Building blocks for nucleic acids; five-carbon backbone
Glucose and Fructose
Used in assembling larger carbohydrates; six-carbon backbone
Same molecular formula, different structures
Formed when a dehydration reaction joins two monosaccharides (water is removed)
Glucose + fructose; transport form of sugar used by plants and harvested by humans for food
Glucose + galactose; present in milk
Glucose + glucose; present in germinating seeds
Three sugar units; oligosaccharides with three or more sugar monomers are attached as short side chains to proteins where they participate in membrane function
the polymers of sugars, have storage and structural roles
A storage polysaccharide of plants, consists entirely of glucose monomers
What stores surplus starch as granules within chloroplasts and other plastids
The simples form of starch
A storage polysaccharide in animals
liver and muscle cells
Where do humans store glycogen?
Polysaccharide that is a major component of the tough wall of plant cells.
Cellulose is a polymer of what?
What does cellulose in human food pass through the digestive tract as?
Microbes use to digest cellulose
Many herbivores have this type of relationship with microbes
A structural polysaccharide and found in the exoskeleton of arthropods
Chitin provides this for the cell walls of many fungi
What type of diverse group of molecules are lipids?
The one class of large biological molecules that do not form polymers
little or no affinity for water
The unifying feature of lipids
Hydrocarbons, form nonpolar covalent bonds
What do lipids consist mostly of to make them hydrophobic?
Fats, phospholipids, and steroids
The most biologically important lipids
Constructed from two types of smaller molecules: glycerol and fatty acids
A three-carbon alcohol with a hydroxyl group attached to each carbon
Consists of a carboxyl group attached to a long carbon skeleton
What happens to fats in water because water molecules form bonds with each other and exclude the fats?
Triacylglycerol (or triglyceride)
In a fat, three fatty acids are joined to glycerol by an ester linkage
Length (number of carbons),and number and location of double bonds
Fatty acids vary in
Saturated fatty acids
Have the maximum number of hydrogen atoms possible and no double bonds
Saturated fats (Solid at room temperature)
What type of fats contains cholestorol and are the type of fat in butter and animal fats?
Unsaturated fatty acids
Have one or more double bonds
Unsaturated fats (Liquid at room temperature)
Fish fats, nuts, olive oil, plant fats
A diet rich in saturated fats may contribute to this disease through plaque deposits
The process of converting unsaturated fats to saturated fats by adding hydrogen
Hydrogenating vegetable oils
Created unsaturated fats with trans double bonds
may contribute more than saturated fats to cardiovascular disease. Ex: "I Can't Believe It's Not Butter")
Certain unsaturated fatty acids
Are not synthesized in the human body, must be supplied in the diet
Omega-3 fatty acids
Essential fatty acids that are required for normal growth and thought to provide protection against cardiovascular disease.
The major function of fats
Storage place for fats in humans and other mammals
Cushions the vital organs and insulated the body
Two fatty acids and a phosphate group are attached to glycerol
The two fatty acid tails are ___________, but the phosphate group and its attachments form a ____________ head.
What phospholipids self-assemble into when they are added to water. The hydrophobic tails point toward the interior
The structure of phospholipids found in cell membranes
Major component of all cell membranes
Lipids characterized by a carbon skeleton consisting of four fused rings
An important steroid and is a component in animal cell membranes
Even though essential, high levels of cholesterol in the blood may contribute to this disease
Have both lipid and protein components; transport fats and cholesterol in the blood
Low Density Lipoproteins
Needed in the maintenance of cell membranes; transport through blood steam
When low density lipoproteins travel through the blood, it builds up on the walls of the arteries and causes what, which can lead to coronary heart disease and heart attacks.
Low Density Lipoproteins
Often referred to as bad cholesterol
High Density Lipoproteins
Reduces the risk of heart disease caused by LDL. Excess cholesterol in the body is bound by this and transported to the liver for disposal. Also removes LDL cholesterol from the wall of the arteries.
Proteins account for more than what percentage of the dry mass of most cells
Structural support, storage, transport, cellular communications, movement, and defense against foreign substances
A type of protein that acts as a catalyst to speed up chemical reactions
Processes of life
Enzymes can perform their functions repeatedly, functioning as workhorses that carry out what?
What are unbranched polymers built from the same set and how many amino acids do they contain?
A biologically functional molecule that consists of one or more polypeptides
Amino Acid Monomers
Polypeptides are a type of
Organic molecules with carboxyl and amino groups
Amino acids differ in their properties due to differing sides chains, called
How amino acids are linked
A polymer of amino acids ranging in length from a few to more than a thousand monomers
carboxyl end (C-terminus) and amino end (N-terminus)
Each polypeptide has a unique linear sequence of amino acids
Consists of one or more polypeptides precisely twisted, folded, and coiled into a unique shape
The sequence of amino acids determine what structure of a protein
What does a protein's structure determine?
Ordered sequences of amino acids each linked together by peptide bond to form polypeptide chains
Determined by how amino acid sequences present their atoms for hydrogen bonding or how R-groups interact
Helical coil e.g. hemoglobin or sheetlike array e.g. silk that results from H-bonding of side groups on the amino acid chains
Result of folding due to interactions among R groups along the polypeptide chain
Complex two or more polypeptide chains to form globular e.g. hemoglobin or fibrous proteins
High temperatures or changes in pH can cause a loss of a protein's normal three-dimensional shape; normal functioning is lost, which is often irreversible.
Polymers of nucleotides e.g. DNA and RNA. Nucleotides consist of a five-carbon sugar (ribose and deoxyribose), a nitrogen-containing base, and a phosphate group.
Phosphate, sugar, and base
Protein is still of protein even if it is
Structural, Enzymes, and functional
Three main types of proteins