Biology Biology the study of life What makes us alive atoms molecules dna oxygenated reproduction movement ability to grow adapt require outside energy source organized function What makes us human Way me move awareness complex body structure and brain emotions build of existing knowledge complex thoughts and voicing opinions way we communicate dna ability to tell the difference between right and wrong ability to use our resources thumbs 4 Things that make us human Complex written and spoken language 2 Large brain 3 Bipedal stand on 2 legs 4 opposable thumb Organizations of humans Chemistry atoms and molecules proteins lipids carbs dna Cellular smallest unit of life Tissue groups of similar cell types Nervous muscular connective and epithelial Organs made up of all tissue types working together to carry out a specific function stomach heart lungs Organ systems multiple organs working together to perform a specific function within the body Organism all organ system working together endocrine Homeostasis Feedback loops The ability to maintain a relatively constant internal environment in the body Despite constant internal external disruptions temp blood glucose The nervous and endocrine systems are key in maintaining homeostasis hormones Changes from the normal tolerance limits results in illness or even death Feedback loops keep the body informed of any changes and also attempt to correct the situation to restore homeostasis Factors in a feedback loop Normal controlled condition Receptor Control center Effectors Normal receptor control center brain effectors to maintain homeostasis 2 mechanisms for maintaining homeostasis Negative feedback loop Immediately reverses the situation to restore homeostasis Ex Blood pressure Most common Immediate reversal Positive feedback loop Must first intensify the situation to restore homeostasis Ex Child birth blood clot ovulation BP Baroreceptor hypothalamus down HR BP Down Uterus contractions activates stretch rec in the cervix pituitary oxytocin hormone intensification escalates Chapter 2 Chemistry Matter anything that has weight and takes up space Elements are basic building blocks of matter that cannot be broken down by chemical means Atoms are the smallest units of an element that retain the elements physical and chemical properties These bond together to form molecules 4 elements make up 96 of the body H O N C Other important minerals K Na Fe Ca Cl I Subatomic particles of atoms Neutrons have a neutral charge Protons are positively charged Neutrons and protons make up the nucleus Electrons are electrically charged and orbit around the nucleus in the electron shells of pro of ele Octet Rule An atom can hold 2 electrons in its inner most shell 8 in the second and 18 in the 3 rd However if an atom have 8 electrons in the 2nd or 3rd it is stable If an atom has not satisfied this octet rule it will react with other atoms to form molecules or compounds Molecules and compounds Moles are made of atoms that are bonded together Can be made of the same atom or different atoms Compounds are also made of atoms that are bonded together But it must be 2 or more different atoms Water co2 o Water co2 Ionic bonds Atoms in this type of bond donate or receive electrons Results in a stable outer shell for both atoms Forms charged particles ions Will dissociate in water Covalent bonds Atoms in this type of bond share electrons Results in a stable outer shell Stronger than ionic bonds will not dissociate in water Hydrogen bonds Weaker than ionic or covalent bonds Can form between hydrogen and oxygen hydrogen and nitrogen and hydrogen and fluorine Can be found within molecules or in between molecules proteins DNA Not strong enough to form a molecule but are very important for shaping proteins and DNA Also responsible for some unique properties of water What are the unique properties of water Water is a polar molecule High heat capacity liquid water does not change temperature quickly Molecules of water cling together surface tension cohesive Water is a great solvent Liquid at room temperature Frozen water is less dense than liquid water Hydrogen bonding and water Hydrogen bonds form between a hydrogen atom in one molecule of water and an oxygen atom in another molecule of water This occurs because water is a polar molecule Polar covalent bonds electrons are shared unequally Electrons are shared unequally Why is water such a good solvent Water is attracted to other polar molecules and or any substance with a charge ions Molecules that will mix with water are hydrophilic Molecules that do not mix with water are hydrophobic Acids and bases Acids are substances that dissociate and release hydrogen ions h Bases are substances that take up hydrogen atoms or release hydroxide ions OH Sodium hydroxide What is the pH scale A measure of hydrogen ion concentration Working scale is between 0 14 with 7 being neutral water A pH below 7 is acidic higher is a base The concentration of ions between each whole number is a factor of 10 Four major macromolecules What organic molecules are found in living organisms 1 carbohydrates sugars 2 lipids fats 3 proteins 4 nucleic acids dna rna What are carbs Made of subunits called monosaccharides Made of C H O In a 1 2 1 ratio Function as short and long term energy storage Found as simple and complex forms Monosaccharide 1 carbon ring as found in glucose Disaccharide 2 carbon rings as found in maltose Polysaccharides made of many carbon rings Glycogen is the storage form in animals stored carbs liver and muscle tissue Starch is the storage form in plants Making and breaking down organic molecules Dehydration synthesis reaction the removal water from 2 smaller molecules in order to link them together to form one larger molecule Making and breaking down organic molecules Hydrolysis reaction the addition of water to a large molecule to break it down into smaller subunits What are lipids Composed of mostly C and H in a 1 2 ratio Hydrophobic molecules Fats oils waxes Purpose used as energy molecules found in cell membranes and can also be hormones Saturated and unsaturated fatty acids triglycerides Fatty acids Composed of hydrocarbon chains May be 4 36 carbons long The hydrocarbon chain is referred to as the hydrocarbon tail The other end contains the carboxyl group Saturated fatty acids Long hydrocarbon chain that does not contain double covalent bonds c c Usually solids at room temperature Usually from animals Increase blood cholesterol
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