Key questions NEXT DEADLINE SUNDAY 6:00
1. How is energy captured by chlorophyll molecules? How is this energy used to decrease entropy during photosynthesis? DONE
Energy is captured by chlorophyll molecules in a process called photosynthesis during which the chlorophyll molecules capture sunlight and convert it into an excited electron. This excited electron is "caught" by NADPH and transferred to a glucose molecule consisting of 6 carbons, 12 hydrogens and 6 oxygens that is being assembled during photosynthesis. The glucose molecule is being assembled from the CO2 in the air and the H2O from the roots that is broken down inside the plant. The carbon dioxide provides the 6 Carbon atoms and 6 Oxygen atoms, while the water provides the 12 Hydrogen atoms and 6 excess Oxygen (which are released back into the atmosphere through the stomata of the plant). This glucose molecule can then be used for energy by the plant. This energy decreases entropy by organizing the molecules into glucose during the process.
2. How is the structure of a leaf ideal for carrying out the process of photosynthesis?
3. Why must the energy in glucose be transferred into many ATP molecules? DONE
Energy in glucose must be transferred into many ATP molecules because glucose is too energy rich so it must be broken down into C02 and H20, and its energy is then transferred into 38 ATP molecules, each containing 7.3 kcal/mole, to allow us to use the energy more efficiently. Most chemical reactions in cells only require about 3-5 kcal of energy to make them go. By turning a glucose molecule into water and carbon dioxide and transferring glucose's energy to ATP from ADP and P our body enhances the energy conversion to about 40%, the excess is our body heat. Cashing in glucose's energy for 38 ATP is like cashing in a $100 at the bank. Either you can pay for something with a $100 with no change, or cash in the bill for 100 $1's. Cashing in the $100 makes more sense because then we can keep the change to spend on something else.The bank is the mitochondria where the glucose is broken down into carbon dioxide and water. Oxidative phosphorylation is a process that takes place in this mitochondrion where Glucose's energy is used to create ATP from ADP and P.
4. How is the energy in glucose transferred into ATP through oxidative phosphorylation? DONE
Glucose is broken down in steps. Glucose is first broken down into CO2 and H2O through cellular respiration, C6H12O6 + 6O2= 6CO2 + 6H2O + energy. The energy in glucose leads to the formation of ATP. The electron carrier NAD+ removes excited electrons from the glucose along with a H+ to create NADH. Now NADH carries the released electron to proton pumps of the inner membrane. The e- will travel through three separate proton pumps each time moving down towards its ground state. As it moves down in each pump energy is given off and this energy is used to change the shape of the proton pump in order to move H+ from the matrix into the inter membrane space. In oxidative phosphorylation, electron transfers occur using specialized proteins embedded in the inner mitochondrial membrane, causing the generation of a proton (H+) gradient across the inner mitochondrial membrane. ATP synthase allows H+ ions to diffuse back into the matrix and uses the free energy released from the turbine like rotation of the enzymes around the ATP synthase to synthesize ATP from ADP and P-.
POSSIBLE BREAK AT THIS POINT FOR A TEST
5. What role does surface area play in determining the structure of leaves, lungs, and intestines? DONE
A large surface area is crucial for leaves, lungs, and intestines to perform effectively and efficiently. Leaves thrive best when they have a large surface area that enables more absorption of sunlight and CO2 than leaves with smaller surface areas. However, a large surface area also poses risks to the leaf: the dangerous evaporation of water into the atmosphere is more likely. In animal lungs, gases are exchanged across moist surface areas, thus, the surface area of the respiratory surface must be large enough to take up enough oxygen for every cell in an animal's body while also disposing of CO2. This gas exchange takes place by diffusion. Somewhat similarly for a human's lungs, alveoli, tiny air sacs on the lungs, have a massive surface area, approximately 100m2, or fifty times the surface area of the skin. The alveoli give the lungs a larger surface area to allow CO2 diffusion and oxygen diffusion to work more effectively. Following the same pattern, the intestinal wall is lined with large circular folds and villi, small projections which add surface area to the lining of the intestines. Villi and their microvilli (smaller surface projections on the epithelial cells of a villi), exponentially increase the surface area across which nutrients are absorbed. This increase of surface area allows for the more efficient absorption of nutrients and minerals across the intestines.
Write a sentence (or 2) to show a relationship between the following sets of terms.
1. entropy, energy, photosynthesis DONE
Photosynthesis is the process by which plants transfer the energy in sunlight into energy stored in sugars such as glucose. In order for the glucose to be created through photosynthesis an energy input is required so order can be produced from disorder, which is the Law of Entropy. The light energy from the sun is this energy input, which therefore allows order to be made from disorder throughout the reaction, allowing glucose to be made from carbon dioxide and water.
2. spongy mesophyll, diffusion, chloroplasts DONE
The spongy mesophyll is the lower half of the mesophyll. The plant cells, with chloroplasts in them, are less compact in the spongy mesophyll than in the palisade mesophyll, the upper half of the mesophyll, which allows the plant to diffuse CO2 into the leaf and O2 out of the leaf faster.
3. phloem, glucose, storage DONE
Phloem tubes are a part of the vein of a leaf that is used to ship sugars, such as glucose, to roots and other cells throughout the plant. The shipped glucose is then stored in parts of the plant, for example the root system, so at night the plant can live off of the storage of glucose since photosynthesis cannot occur without sunlight.
4. epidermis, cuticle, dehydration DONE
The upper epidermis is a transparent protective layer that secretes a waxy cuticle to not only stop water from remaining on the leaf and weighing it down and growing mold, but also to prevent water loss by evaporation, which would lead to dehydration of the plant.
5. photosynthesis, mitochondria, ATP DONE
Photosynthesis is the process that plants use to harvest the suns energy in the form of elevated ("excited") electrons. These electrons are excited in the chloroplast, specifically in the chlorophyll. NADPH transfers these excited electrons in their energized states to be used as energy to synthesize 6CO2 & 6H2O into glucose and O2. While the O2 is given off into the atmosphere, the glucose is then broken down in the mitochondria to give off energy to combine ADP and P. When put together, the two compounds form ATP, and each ATP has some of the energy released by the breakdown of glucose (38 ATP can be synthesized by the energy released from one glucose molecule).
6. H+ ions, intermembrane space, ATP DONE
A proton pump moves H+ ions from the matrix of the mitochondrion against the concentration gradient into the intermembrane space of the mitochondria. The H+ ions then diffuse back through the inner membrane by way of the ATP synthase transport protein into the matrix where the energy is transferred into ATP, in order to power manifold functions in the body
7. proton pump, electrons, water, O2 DONE
The proton pump is involved in producing ATP in the mitochondrion. An excited electron is attached to the proton pump from the molecule NADH (the molecule that carries it to the proton pump). The electron goes down to its ground state energy level because the energy goes into pumping the H+’s through the pump. The problem is, we cannot let the electrons accumulate at the front of the pump, so the electrons combine with protons and O2 to form H2O (this is why you breathe oxygen). This way the electrons do not build up and the proton pump can run smoothly because the electrons are removed from the pump as they combine with the H+ ions in the matrix and O2 which forms water.
POSSIBLE BREAK AT THIS POINT FOR A TEST
8. trachea, esophagus, epiglottis DONE
The job of the epiglottis, a flap of cartilage located at the base of the tongue, is to direct food to the esophagus rather than to the trachea, or windpipe. The esophagus connects the throat to the stomach, and is the tube through which all food is carried.
9. alveoli, hemoglobin, capillary DONE
In the lungs, bronchioles dead-end at air sacs, called alveoli, where the diffusion of O2 and CO2 takes place. The O2 diffuses from the alveoli into the capillaries with the help of the addition of hemoglobin in our red blood cells, an iron-containing pigment that is used to transport oxygen to capillaries in body tissues. The CO2 diffuses from the capillaries to the alveoli. This all happens by simple diffusion, going down concentration gradients, not against them.
10. villi, intestines, active transport DONE
Villi are finger-like projections inside of the intestines that add to the overall surface area inside of the intestines. This added surface area allows for an increased amount of nutrients, for example glucose, to pass into the bloodstream by way of active transport.
11. left atrium, pulmonary artery, aorta
Blood travels out of the heart from the right ventricle through the pulmonary artery to the lungs where it moves through the capillaries and back through the pulmonary vein. The pulmonary vein leads to the left atrium and the blood then moves to the left ventricle and out of the heart through the aorta.
