macromolecules Flashcards
What are the four categories of large biological molecules?
Carbohydrates, Lipids, Proteins, Nucleic Acids.
What does hydrolysis do?
Hydrolysis adds water and reverses the dehydration reaction, as seen in digestion.
How are macromolecules formed from monomers?
Through a dehydration reaction (condensation), which removes a molecule of water.
What are carbohydrates made of?
Simple sugars (like glucose and fructose) and polymers of sugar (such as glycogen, starch, and cellulose).
What is the role of carbohydrates in plants?
They provide building material (strength) and storage energy (ATP).
What is the primary function of carbohydrates in animals?
serve as a primary source of energy (ATP), dietary energy, and storage energy.
What is a monosaccharide?
A monosaccharide is a simple sugar that serves as a monomer and main fuel for cellular work (e.g., glucose).
What are disaccharides?
Disaccharides are double sugars formed by linking two monosaccharides via glycosidic bonds in a dehydration reaction.
What is the process of cellular respiration using glucose?
Glucose + Oxygen → 32 ATP + CO2 + Water.
Name some common disaccharides.
Lactose (milk), maltose (beer), sucrose (table sugar).
What is high-fructose corn syrup?
A sweetener made by converting glucose in corn syrup to a sweeter fructose.
What is the average sugar consumption per year in the U.S.?
Approximately 45 kg (100 lbs) to 150-170 lbs per year, primarily from sucrose and high-fructose corn syrup.
How do taste receptors affect sweetness perception?
Sweetness depends on how well the molecules fit into the sweet receptors. For example, glucose fits better than sucrose, and fructose fits the best.
What is glycogen and where is it stored?
Glycogen is a polysaccharide made of glucose molecules, stored in the liver and muscles as an energy reserve.
What are artificial sweeteners and their effects?
Artificial sweeteners like Aspartame (150X sweeter than sugar), Saccharin (450X), and Splenda (600X) are designed to fit better with sweet receptors.
What is starch and its function in plants?
Starch is a polysaccharide that stores energy in plants, made up of amylose and amylopectin.
What is cellulose and what is its function in plants?
cellulose is a polysaccharide that provides structural strength to plant cells and is indigestible in humans, acting as fiber.
What are the functions of fats in the human body?
Energy storage, cushioning, insulation, and forming membranes.
What is a phospholipid made of?
A glycerol molecule (hydrophilic head) and three fatty acid molecules (hydrophobic tail) joined by a dehydration reaction.
What is the difference between saturated and unsaturated fats?
Saturated fats have no double bonds and are solid at room temperature, while unsaturated fats have double bonds and are liquid at room temperature.
Why are saturated fats linked to cardiovascular problems?
Saturated fats can increase LDL cholesterol and contribute to plaque buildup in arteries (atherosclerosis).
What are trans fats and why are they harmful?
Trans fats are created by hydrogenating unsaturated fats, making them solid at room temperature. They are harmful because they increase bad cholesterol (LDL) and decrease good cholesterol (HDL).
What are steroids made of?
Steroids have a carbon skeleton with four fused rings. Their function is determined by the functional groups attached to these rings.
What groups are present in all amino acids?
A carboxyl group (-COOH), an amino group (-NH2), a hydrogen atom, and a unique R group.
What are anabolic steroids and why are they controversial?
Anabolic steroids mimic testosterone, have health risks, and are sometimes abused by athletes to enhance performance.
How much energy does 1 gram of fat and 1 gram of carbohydrate provide?
1 gram of fat provides 9 calories, while 1 gram of carbohydrate provides 4 calories.
What are the health risks of excessive consumption of saturated/trans fats and sugars?
Excessive saturated/trans fats raise LDL (bad cholesterol) and lower HDL (good cholesterol), leading to cardiovascular problems. Excessive sugars contribute to diabetes, obesity, and hypertriglyceridemia.
What are the building blocks of proteins?
Amino acids, 20 kinds (9 essential, 11 non-essential).
How are proteins formed?
By linking amino acids through peptide bonds in a dehydration reaction, forming polypeptides.
What are the major types of proteins and their functions?
Structural proteins: Provide support.
Storage proteins: Store amino acids for growth.
Contractile proteins: Aid in movement.
Transport proteins: Transport substances.
Enzymes: Catalyze chemical reactions.
What is the primary structure of a protein?
The unique sequence of amino acids in a long chain, determined by the gene sequence.
What are the two main types of secondary protein structures?
Alpha helix (right-handed coil) and beta-pleated sheets (folded strands).
What is protein denaturation and what factors can cause it?
Denaturation is the unraveling of a protein, which leads to loss of function. It can be caused by unfavorable changes in temperature or pH.
What determines the tertiary structure of a protein?
The 3D shape of the protein is determined by interactions between the R groups of amino acids, including ionic bonds, hydrogen bonds, disulfide bonds, and hydrophobic interactions.
How do enzymes work?
Enzymes are catalysts that speed up reactions by lowering the activation energy and binding to specific substrates at their active site.
What is competitive inhibition in enzyme activity?
Competitive inhibition occurs when an inhibitor competes with the substrate for binding to the enzyme’s active site.
What are endocrine disruptors?
Chemicals that mimic hormones, like estrogen, and disrupt the body’s endocrine system, causing health problems.
Name some examples of endocrine disruptors.
Pesticides (DDT), industrial chemicals (PCBs, dioxins), plastic softeners (phthalates), and phenol compounds (bisphenol A).
What diseases are associated with protein misfolding?
Alzheimer’s disease, Mad Cow disease, Parkinson’s disease, Sickle cell anemia, and Cystic fibrosis.
What is the structure of DNA?
DNA consists of two strands forming a double helix, with nucleotides linked by phosphodiester bonds to form a sugar-phosphate backbone.
How do the base pairs in DNA match up?
A (adenine) pairs with T (thymine), and G (guanine) pairs with C (cytosine).
How is RNA different from DNA?
RNA is single-stranded, and uracil (U) replaces thymine (T), so A pairs with U in RNA.
