bio 121 exam 3 povenelli ull questions and answers well defined

The early earth's atmosphere had almost no free oxygen (O2). Now it is almost 20% O2. Where did all this O2 come from? - correct answers Photosynthesis Endocytosis and exocytosis are important for what? - correct answers Endocytosis- vesicle pinches inward and moves a bubble of solutes into cells, membrane dissolves in cell and frees them (NO atp) signals on the outside membrane attract what we need and enfold when they come near exocytosis - send them out (No atp) They regulate what is in the cell, cell homeostasis Glucose, fatty acids, and proteins can all be used to make the principal energy carrying molecule in cells. What is this molecule? - correct answers ATP (Adenosine Tri-Phosphate) Describe photosynthesis in general terms. - correct answers Converts solar energy into the chemical energy of carbohydrates which not only sustains the plant but all other life on Earth. What happens to cells in hypertonic versus isotonic solutions? - correct answers Isotonic: equal balance of solute in the cell and outside it Hypertonic: More solute outside than inside Osmosis involves water diffusing through a membrane. What controls this movement? Can you describe osmosis in general terms? - correct answers net flow of water through membranes, Water will diffuse through a membrane from an area with more water to an area with less water. Osmotic pressure: Tendency for water to move into any cell In class we learned that Dr. Peter Agre won the Nobel Prize in 2003 for his discovery of aquaporins. What are this molecules and why are they important? - correct answers Aquaporins: Specialized water channels (in vs out) What is passive transport and active transport (and their steps) and what role does ATP play? - correct answers Passive transport-No energy needed, shape allows to go through Active transport Primary transport: H+ pumps out Secondary transport: H+ in along with another molecule Moves molecules against concentration gradient Stanley Miller and Harold Urey's classic experiments showed that organic molecules could have arisen on a lifeless Earth. Describes these experiments and their purpose and results. - correct answers Stanley's Miller's & Harold Urey's experiments Showed that organic molecules could have arisen on a lifeless Earth. All life are made from inorganic particles ALL life is built on DNA Tried to create life, create conditions and let it happen What are the three major branches of life? - correct answers Archaea, Eubacteria, and Eukaryotes Why are passive diffusion and facilitated (passive) diffusion are called "passive"? - correct answers They dont require atp What are the major structural differences between prokaryotic cell and eukaryotic cells? What are the similarities? - correct answers Plant cells have chloroplasts Eukaryotic cells contain membrane-bound organelles, including a nucleus. Eukaryotes can be single-celled or multi-celled, such as you, me, plants, fungi, and insects. Bacteria are an example of prokaryotes. Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle. Why is the rough endoplasmic reticulum described as "rough"? What are lysosomes and what do they do? - correct answers It is covered in ribosomes making it look textured, lysosomes takes out the trash so individual molecules can be used, breaks things down Which types of cells have membrane-enclosed organelles? - correct answers Eukaryotes Which forms of life have a plasma membrane (phospholipid bilayer) that separates the inside of the cell from the exterior environment? (trick question) - correct answers all What planets will be in the "habitable zone" of our solar system 12.5 billion years from now? What will happen to our sun? - correct answers Jupiter and Saturn. The sun will expand. Give some examples of kinetic and potential energy. What characterizes each? - correct answers Kinetic- me throwing these hands, potential- a ball at the top of a hill not rolling yet or food being stored as energy Kinetic got motion, (boys in motion), potential about to be used but not yet What are the PRODUCTS of photosynthesis? - correct answers Glucose and O2 Where does the O2 released during photosynthesis come from? - correct answers CO2 and H2O Photosynthesis occurs in two stages: the light reactions and the dark (C3 or Calvin) reactions. Describe these reactions at the level we discussed in class. What does each stage produce? Which stage uses oxygen? Which stage uses water? Which stage fixes carbon from C02? Where does these reactions occur in the cell? - correct answers Light Reactions--Light is absorbed by the chlorophyll and stored as ATP -Water is broken down to release oxygen gas -H+ ions are stored in a carrier molecule called NADPH Dark reactions- The ATP and NADPH is used in the conversion of the CO2 to glucose in the Calvin cycle Why do green plants look green to the human eye? - correct answers All other colors get absorbed; the green light reflects (technically blue and yellow) What is cellular respiration? In what organelle does it occur? - correct answers Mitochondria: organelles of cellular respiration Cellular respiration: uses oxygen to harvest energy from molecules of sugar. The energy is stored as chemical energy in molecules of ATP. In class, we discussed the analogy between cell phone reception and photosynthesis. What was the point of the analogy? What part of the electromagnetic spectrum do each use? - correct answers Energy from sunlight hits the macaron chloroplast and makes energy Flow of electrons from energy builds sugar as an output Cell Phones take advantage of elevtromangteic spectrum On the long end of microwave band What is a cytoskeleton? Which kinds of cells have them? What are they for? - correct answers all cells have a cytoskeleton , network of fibers made of protein for anchorage and support What are vacuoles? Which kinds of cells have them? What are they for? - correct answers sacks within plant and algae cells that hold water , used for storage of food water, atp and pigments What is the plant wall made from? - correct answers The cell wall of a plant cell is a rigid protective layer made of cellulose that helps maintain cell shape Reactants are high energy, products are low energy, like burning a fire, using glucose - correct answers exergonic reaction Products are higher energy than reactants when chemical reaction is storing energy like charging a battery, photosynthesis; - correct answers endergonic dense levels of glucose - correct answers cellulose Where is MOST of the ATP made in cells? - correct answers Mitochondria (the powerhouse of the cell) What organelle has been implicated in Alzheimer's patients and what is the consequence of its malfunction for their brains? - correct answers this is covered in lecture 4 notes slides 24-35 What kind of reaction is the conversion of ATP to ADP and P? How is adenosine diphosphate (ADP) turned into adenosine triphosphate (ATP)? - correct answers hydrolysis, energy is released (exergonic) , and ATP is converted to adenosine diphosphate (A