BIO 201 Lecture 1 Properties of Living organisms Comprised of cells motoneurons cell bodies of neurons located in bottom of the back run to feet one experiment to disclaim balloonist theory of muscles even when specialization occurs there are some functions each individual cell has to do There are different levels of organization cells Molecular what they do how there place determines function in Muscles contract through shape changes in certain molecules Cellular Tissues cellular specialization in a specific tissue may occur Organs Organ systems Organisms Control mechanisms functions occur at all levels Behavioral control mechanism walking into a AC building when its hot out Users of Energy Potential Energy food carbs chemical potential energy is stored in chemical bonds in complex molecules breaking LG molecules into SML molecules releases energy then want to trap energy or ATP do this by adding a phosphate to ADP to make it ATP Do this in Small Steps Ability to Respond to environment detecting changes in environment external responses walking into AC building when hot Getting shelter in rain internal repsonses blood sugar internal temp do this through senses internally brains know exact angle of every joint in body and rate at which they are changing HOMEOSTASIS regulation of stable internal environment despite changing external environment 98 6 is ideal body temp b c most efficient temp for body functions Increase in temp leads to increase in reaction rate allowing more efficient activity Bio reaction occurs until temp is too high and starts to unravel proteins or DENATURE Protective mechanisms passing out temperature response to chemicals released in response to chemicals release during foreign invaders swelling pain etc pH acidity or basic nature of a solution 7 acidic 7 basic Body fluids are about 7 3 7 4 Somach fluids are around pH of 2 Proteolytic enzymes to chemically breakdown proteins in stomach to maintain pH Many factors affect pH sweating breathing pH lowers as CO2 is released into blood cells Carbonated beverages coke 2 3 pH Urine may be used to maintain body fluids by retaining or releasing certain amounts of H2O into urine Growth Development grow by increase in cell number grow by increase in cell size working out in increasing cell size Ability to Reproduce sexual Chromosome are germ cells combine and genetics of each parent are present in offspring asexual Adapt to the environment Traits have to confer an adaptive advantage to the organism inheritable traits increase survival form from mutations Maladaptive BAD trait causes deficiency harm Individuals that would not normally survive are living past expectancy due to advancements in medicine causing them to adapt when naturally they would die out Variation in population Lg population MOLECULES CAN CHANGE SHAPE IN MEANINGFUL WAYS molecules such as proteins have meaningful ways of shape changing muscle contractions actin mysin Nerve membranes allow ions in through channels which change shape to allow certain ions in molecule shape change Pepsin enzyme made by cells lining stomach nonspecific protease what keeps it from eating cells that make it made in an inactive shape change activates it operates maximally at pH of 2 to break down peptides Energetics Mucus and cell turnover prevent acid from eating up stomach Thermodynamics 1st Law Energy can neither be created nor destroyed but can be converted b w forms sucrose on cheerios breaking sucrose into monosaccharides some stored as ATP in body converted energy from one form to another and some is given off as heat 40 efficient 60 is lost as heat 2nd Law Entropy measure of randomness spontaneously increases into a more random state constantly until degraded to heat energy degrading to heat is going towards a more random state will go against this law when energy is put INTO the system Metabolism total of all transactions of energy in our cells Catabolism breaking down producing energy EXERGONIC rxn Anabolism building up energy is required Enzymes catalyze reactions lower energy of activation Products are produced in a quicker physiological amount of time Co factors that modify enzyme control the activity of the enzyme and affect reactions downstream from this reaction Phosphorylation adding a phosphate group to increase the amount of energy in a molecule ATP such a universal molecule because it can change shape and it increases potential energy of molecules by breaking a phosphate off and adding it to molecules Negative feedback some chemical produced in a reaction sequence feeds back to a certain reaction and manages the reaction by either aiding it or hindering it Positive feedback product enhances the reaction and furthers the reaction always has to have some special mechanism to turn it off Components of Cells Water 85 Proteins 10 Lipids 2 Salts 1 5 Nucleic Acids 1 1 Carbohydrates 04 Hydrophobic non polar Hydrophilic Polar Organic Molecules Carbon containing molecules Carbon Form chemical bonds 4 Covalent bonds chains rings Dbl trpl bonds change shape of molecule Electroneutral Bonds No exposed charges Non polar and Hydrophobic Carbohydrates simple sugars Proteins peptides polypeptides Amino acids compose proteins Lipids and Phospholipids Fats triglycerides hydrophobic NON polar glycerol is the back bone of molecule made of 3 carbons Glycogen Carb storage form in animal cells made up of polymer of thousands and thousands of glucoses Starch CHO storage form for plant cells Chitin exoskeleton of arthropods CHO plus amino acids Cellulose CHO polysaccharide Most animals do not have an enzyme to break down this molecule Saturated animal sources Shape allows for tighter packing and formation of weak bonds b w lipid molecules ALLOWS TO BECOME SOLID b c of density high caloric volume Unsaturated plant sources double bonded Bend in shape doesn t allow to become solid stay liquid See Ch 2 3 separate glycerol from fatty acids to breakdown high density and low density lipo proteins circulating lipids that bind to a polar molecule to be transferred through blood Phospholipids one part of the molecule is polar and can mix w water HEAD the other part is non polar TAIL polar heads assoc w water on the outside and the tails assoc w each other to form a central hydrophobic region that excludes water Phospholipid bi layer wih a central hydrophobic region excludes water and other polar molecules Backbone of bio membranes selectively permeable Aquaporins Always open allow water