Biology Midterm Study Guide Chapters 1 3 4 5 6 Plants animals fungi protists bacteria are examples of living organisms Prologue Biology is the study of life Biotic a living organism Abiotic not living Steps of the Scientific Method 1 Problem 2 Hypothesis 3 Design an Experiment 4 Run Conduct 5 Conclusion What is a Variable The part of an experiment that changes What is a Control Group The part of an experiment that doesn t change o A control group is necessary for an experiment because we need to know what factor that is not going to change so we can see what different things happen to the variables What is a Hypothesis An educated guess that has not been proven An answer to a scientific problem the explanation for an observation What is a Theory What is a Law A hypothesis that has been proven A bunch of theories put together Protons are positive neutrons are neutral electrons are negative A substance composed of atoms that are chemically identical alike in their of protons and cannot be broken down into a simpler substance Chapter 1 What is an element 6 Most Common Elements 1 Carbon 2 Hydrogen 3 Nitrogen 4 Oxygen 5 Phosphorus 6 Sulfur What is a molecule another The smallest unit of a compound composed of atoms covalently bonded to one When atoms are joined a bond forms Energy is stored in a bond so when a bond breaks either free energy or heat energy is released Atoms make bonds because they want to fill the empty spaces on their electron shell How many bonds do they like to make HONC 1234 What is a chemical reaction When 2 or more atoms molecules come together and interact w each other Isotope atom with a different number of neutrons Covalent Bonds are not charged they share electrons a Polar b Non polar i When they share the electrons one atom is closer to it then another i When they share the electrons equally 50 50 Ionic Bonds are charged because they steal electrons from other atoms Cohesion when water molecules bond with other water molecules Adhesion when a water molecule bonds with another molecule not water What is pH The measure of H ions o On a scale from 0 14 7 would be neutral 0 6 would be acids 8 14 would be bases The acids have a high concentration of H low OH The bases have a low concentration of H high OH Organic compounds that are made up of carbon atoms Ex hydrogen oxygen nitrogen carbon Proteins like enzymes transport proteins are made out of amino acids They help to fight against disease and helps to speed up chemical reactions in enzymes Primary determines the sequence bond to form a strand of alpha helix Secondary as they start folding up beta pleated sheets are made Tertiary hydrophobic part of the protein curls in the inside forming a ball Quaternary when several folded balls of protein form to make a bigger ball Lipids like waxes sterols are made of glycerol and fatty acids They provide long term energy storage and protects vital organs Carbohydrates like starch cellulose glucose are made of monosaccharides They provide short term energy storage and help with plant structure Nucleic Acids like RNA and DNA are made of nucleotides They store genetic information and gives instructions on how to build proteins They re made up of a phosphate sugar base double stranded DNA adenine guanine cytosine thymine single stranded RNA adenine guanine cytosine uracil Chapter 3 What is the purpose of the cell membrane To enclose the organelles and cytoplasm in the cell To protect the cell filters what goes in and out Parts of the cell membrane a Phospholipids act as a barrier for the cell hydrophilic heads hydrophobic tails b Proteins act as a doorway for the bigger molecules to pass through c Carbohydrates have glycans attached to send messages communicate w other cells d Cholesterol slows down the movement of phospholipids What molecules can pass easily though the membrane Small polar and non polar molecules What molecules need help from transport proteins Larger uncharged molecules and ions Passive Transport requires no energy because it moves from a high to low concentration a Diffusion when the molecules move through the phospholipids easily b Facilitated diffusion when molecules need help so move through the transport protein Active Transport requires energy because it moves from a low to high concentration gradient a Transport protein take the molecules and pushes it from low to high b Endo exocytosis moves from low to high with the help of vesicles How does surface area affect diffusion The larger the surface area the higher the diffusion rate because there is more space surface area in which to diffuse in Hypotonic the low concentration the solution is in Hypertonic the high concentration the solution is in Isotonic equilibrium where the solution is in Osmosis is when water moves from a low to high concentrated solution through a membrane Turgor a cell s swelling against its cell wall caused by the pressure of the cell s contents Chapter 6 Scientists that contributed to cell theory Robert Hooke discovered cells by looking at cork Robert Brown discovered the nucleus of the cell Theodor Schwann found out that animals were made out of cells too Anton van Leeuwenhoek discovered protists by looking at water What is a cell Cell theory states that The basic living unit of structure and function cannot be broken down 1 All living things are made of cells 2 Cells are the basic unit of structure and function 3 All cells come from pre existing cells Light Microscope Advantage Disadvantage You can see the living organisms inside without killing the sample They have to be large organisms Electron Microscope You can see very small organisms that are in the cell It kills the sample because it uses a lot of power Prokaryotes don t have organelles are unicellular no nucleus and simple Ex bacteria Eukaryotes have organelles are multicellular have a nucleus and are more complex Ex plants What is a colony A group of unicellular microorganisms living together All the cells are similar they move together are coordinates and each cell has a specialized roles Ex Volvex Disadvantages are that they can t grow to be very large and only some can reproduce Multicellular organisms contain organ systems are large more complex then single celled organisms They have systems so most cells are not in direct contact with outside environment because a division of labor occurs and because many individual cells can t work together without regulation coordination