8Lab - Pillbug Preference ● A hypothesis is a formulated statement of predicted behaviors.● A controlled experiment allows scientists to test hypotheses and to draw conclusions basedon reproducible results.● A controlled experiment allows comparison between a control group and a test(experimental) group that has been exposed to an experimental factor (the variable).● In the analysis phase, the results of the experiment are examined for agreement with thehypothesis. Any differences that are observed between the two groups can be attributed tothe effects of the experimental factor.● The conclusion includes a representation of the results and a discussion regarding theconfirmation or rejection of the original hypothesis. The Biology of Diet and Energy Unit 1 Module 1: ❖ Energy ➢ Energy is the capability to do work (transfers between two things when doing work) ➢ Forms of energy: Solar Energy - energy from the sun; source of energy for all life Chemical Energy - energy found in bonds of chemical compounds; energy from the bonds in carbohydrates, fats, and proteins Mechanical Energy - energy of motion (kinetic energy) or position of the object before it moves (potential energy); the energy of position or the position of an object before it moves ➢ Laws of Energy: First Law of Thermodynamics - energy can be converted between forms Second Law of Thermodynamics - conversion of energy from one form to another results in a loss of energy as heat; means that cells must have a constant source of energy for their system to remain organized and functional ■ Laws use the information obtained from theories to describe natural phenomenon ➢ Entropy is the loss of organization ■ It is the measure of disorder in a system; cells must constantly acquire energy to prevent entropy; it is explained by the second law of thermodynamics ❖ Chemistry of Energy ➢ Adenosine triphosphate (ATP) is a type of nucleic acid used as the energy currency for cells ■ ATP is an abbreviation for the molecule that serves as the energy currency of cells ➢ Allows energy-releasing reactions to be coupled with energy-requiring reactions ➢ Energy is contained within the bonds between phosphate molecules ❖ Flow of Energy➢ The production of chemical energy, such as the bonds in carbohydrates and ATP occurs at the cellular level ➢ Mitochondria are organelles that complete the breakdown of carbohydrates to produce energy that is used to build ATP molecules ➢ This process requires oxygen and carbohydrates, and produces carbon dioxide and water ➢ Chloroplasts are organelles that capture solar energy and use it to convert water and carbon dioxide to carbohydrates ➢ Notice that the by-products of one process are used as the reactants for the other process. This is referred to as the cycling of molecules ➢ It is actually the cycling of molecules between chloroplasts and mitochondria that allows a flow of energy from the sun through all living things. ❖ Organic Nutrients ➢ An organic nutrient is a molecule containing both carbon and hydrogen atoms. ➢ Organic molecules contain chains of carbon and hydrogen atoms commonly called hydrocarbons ■ The chemical reactivity of an organic molecule is largely determined by the types of functional groups attached to the hydrocarbon chain ❖ Functional Groups ➢ Functional groups are attached to hydrocarbon chains to provide chemical reactivity to organic molecules ➢ Nutrients are long chains of smaller molecules. The long chains are called polymers and the smaller components that build them are called monomers ➢ Monomers are joined together into polymers through dehydration synthesis reactions ➢ Polymers are broken down into monomers through hydrolysis reactions ❖ Energy Nutrients ➢ Energy nutrients all have potential energy stored in their bonds ■ Carbohydrates are energy nutrients that include sugars and polysaccharides ● Carbs are processed by the body by…. ■ Lipids are energy nutrients that include triglycerides and cholesterol ● Lipids are processed by the body by... ■ Proteins are energy nutrients that include peptides, polypeptides, and enzymes ● Proteins are processed by the body by…. ❖ Carbohydrates ➢ Are hydrophilic (easily moved within bodies and cells) ➢ Are quickly accessed as an energy source (preferred energy source) ➢ Can form long polymers that are easily broken down by digestive enzymes ➢ Are formed through dehydration synthesis reaction ➢ Types of Carbohydrates: Monosaccharides - single carbohydrate units, sometimes called simple sugars; EX: glucose Disaccharides - combinations of two monosaccharides, one of which is usually glucose EX: lactosePolysaccharides - long chains of glucose molecules, may be either branched or unbranched EX: fiber; starch is a polysaccharide used for long-term energy storage in plants ➢ Glycogen is a polysaccharide used for short-term energy storage in animals ➢ Fiber is a polysaccharide used for the structural components of leaves, stems, and roots within plants ❖ Gluten ➢ Gluten is a natural protein (not carbohydrate) found in cereal grains. ❖ Lipids ➢ Lipids are used for long term energy storage; are hydrophobic; include triglycerides (fats) and oils ❖ Triglycerides ➢ Triglycerides are composed of a glycerol molecule and 3 fatty acids ■ The majority of fats in our diets are triglycerides ■ Fatty acids can be saturated or unsaturated Saturated - carbons are bound to two carbons and two hydrogens, are hydrophobic, form long straight chains Unsaturated - carbons are bound only to hydrogens, are less hydrophobic, form bent chains ❖ Cholesterol ➢ ❖ Proteins ➢ Proteins are composed of amino acids ➢ Amino acids consist of a central carbon linked to an amino group, a carboxyl group, and a variable R group. ■ Amino acids are built through dehydration synthesis reactions ➢ Peptide bonds link amino acids together to form polypeptides; the bonds are strong so they take more time to digest and are slower to release energy ➢ Protein Structure: Primary structure - a linear sequence of amino acids Secondary structure - amino acids interact with each other Tertiary structure - 3D molecules are made, protein is functional; maintained by covalent ionic and hydrogen bonds between the R groups in the amino acid Quaternary structure - different polypeptides interact with each other forming more