Science Flashcards
(26 cards)
What is digestion?
Digestion is the process of mechanical and chemical breakdown of nutrients into smaller components in order to be absorbed into the body (blood stream).
What are carbohydrates?
Carbohydrates include monosaccharides (fructose and glucose) that combine to form disaccharides (sucrose and maltose) and polysaccharides (starch and glycogen). They consist of the elements carbon, hydrogen, and oxygen.
What are lipids?
Lipids include glycerides (made from fatty acids and glycerol) and steroids. They consist of the elements carbon, hydrogen, and oxygen.
What is the difference between carbohydrates and lipids?
Although carbohydrates and lipids consist of the same elements, the ratios and molecular structures differ predictably.
What are proteins?
Proteins are one or more peptides which consist of a sequence of amino acids. They consist of the elements carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.
What is metabolism?
Metabolism is the web of all enzyme-catalyzed reactions in a cell or organism.
What is anabolism?
Anabolism is the synthesis of complex molecules from simpler molecules, including the formation of macromolecules from monomers by condensation reactions.
What are condensation reactions?
Condensation reactions are chemical reactions in which reactants are joined together to form a product with water as a by-product.
Provide an example of a condensation reaction for carbohydrates.
Carbohydrates: Monosaccharide + Monosaccharide –> Disaccharide + Water
Example: Glucose + Glucose –> Maltose + Water
What is catabolism?
Catabolism is the breakdown of complex molecules into simpler molecules, including the breakdown of macromolecules into monomers by hydrolysis reactions.
What are hydrolysis reactions?
Hydrolysis reactions are chemical reactions in which reactants are separated using water to form products.
Provide an example of a hydrolysis reaction for carbohydrates.
Carbohydrates: Disaccharide + Water –> Monosaccharide + Monosaccharide
Example: Maltose + Water –> Glucose + Glucose
What is Collision Theory?
Collision Theory states that a chemical reaction will occur if three criteria are met: reactants collide, with the correct orientation, and with enough energy (E ≥ Ea).
What is activation energy (Ea)?
Ea is the minimum amount of energy required for a chemical reaction to occur.
What is reaction rate?
Reaction rate is the change in a quantity per unit time.
How is reaction rate defined in terms of reactants and products?
In terms of reactants, it is the rate at which they disappear (negative change). In terms of products, it is the rate at which they appear (positive change).
What is the equation for reaction rate?
The equation is change in amount ÷ change in time.
What factors affect reaction rate?
Factors include temperature, concentration, surface area, and pH.
What is an enzyme?
An enzyme is a biological (protein) catalyst that increases reaction rate but is not used up.
What is enzyme specificity?
An enzyme binds to and reacts with specific substrates according to the lock-n-key model.
What is the lock-n-key model?
In the lock-n-key model, the enzyme is the lock, the active site is the keyhole, and the substrate is the key that fits into the active site.
What is enzyme catalysis?
An enzyme increases reaction rate but is not permanently changed in the reaction.
How does temperature affect reaction rate?
Changing temperature affects the average kinetic energy of particles, which changes the speed of particles and the frequency of collisions, thus affecting reaction rate until the enzyme denatures.
How does concentration affect reaction rate?
Changing concentration affects the number of particles within a specified space, which changes the frequency of collisions and the probability of successful collisions until all active sites are used.
