Big Idea 2 Biological Systems Utilize Free Energy to Grow, to Reproduce, and to Maintain Dynamic Homeostasis

2-1: Describe an example of a coupled reaction (i.e. an energetically favorable reaction coupled with an energetically unfavorable reaction)

Photosynthesis & the Krebs Cycle Glucose gets broken down into pyruvate, which releases energy for phosphorylation of ADP to ATP (substrate-level phosphorylation)

2-2: Describe the various strategies organisms use to regulate body temperature and metabolism.

2-3: Describe how the light-dependent reactions of photosynthesis power the light- independent reactions of photosynthesis.

2.3: Describe how the light-dependent reactions of photosynthesis power the light- independent reactions of photosynthesis. The ATP and NADPH created by the light-dependent reactions of photosynthesis are used to power the light independent reactions. The high-energy bonds in these molecules are broken and the energy is used to create glucose and other sugars in the calvin cycle.

2-4: Describe how the electron transport chain captures free energy from electrons in a series of coupled reactions that establish an electrochemical gradient across membranes.

1. In cellular respiration, electrons delivered by NADH and FADH2 are passed to a series of electron acceptors as they move toward the terminal electron acceptor, oxygen. In photosynthesis, the terminal electron acceptor is NADP+. 2. The passage of electrons is accompanied by the formation of a proton gradient across the inner mitochondrial membrane or the thylakoid membrane of chloroplasts, with the membrane(s) separating a region of high proton concentration from a region of low proton concentration. In prokaryotes, the passage of electrons is accompanied by the outward movement of protons across the plasma membrane. 3. In cellular respiration, decoupling oxidative phosphorylation from electron transport is involved in thermoregulation

2-5: Describe the reactants, products, and electron carriers involved in the steps of cellular respiration. Glycolysis Kreb’s Cycle Electron Transport Chain

2-5: Describe the reactants, products, and electron carriers involved in the steps of cellular respiration. Glycolysis Reactants: Glucose + 2 NAD+ + 2 Pi + 2 ADP Products:2 pyruvate + 2 NADH + 2 ATP + 2 H2O Phosphorylation Krebs's Cycle Reactants: glucose, oxygen Product: carbon dioxide, water, and ATP Electron carriers: NADH Electron Transport Chain Moves electron from high concentration to low concentration Electron carriers: NAD+

1.2

2-6 Smaller cells have a more favorable surface area to volume ratio because if you have a greater surface area you can release and absorb more nutrients with your environment.

2-7: Describe the fluid mosaic model of the cell membrane.

Describe the fluid mosaic model of the cell membrane Main fabric of membrane composed of amphiphilic or dual-loving phospholipid molecules Integral proteins integrated completely into membrane structure with their hydrophobic membrane-spanning regions interacting w/ hydrophobic regions of the phospholipid layer Carbohydrates (third component of plasma membrane) always found on the exterior surface of the cell where they are bound either to proteins (forming glycoproteins) or to lipids (forming glycolipids)

2-8: Describe examples of passive transport and active transport. Passive transport Simple diffusion Facilitated diffusion Active transport Na+/K+ pumps Proton pumps

2-9: Describe cell structures and functions in prokaryotes and eukaryotes ProkaryotesEukaryotes

Describe cell structures and functions in Prokaryotes and Eukaryotes PROKARYOTES: -Cell wall keeps keeps shape and protects from external influences. -cytoplasm contains single dna molecule -Mesosomes are present inside the cell membrane and plays a vital role in cellular respiration, and cell division EUKARYOTES -Nucleus contains DNA -Mitochondria syntheseizes ATP -cell membrane only lets certain things in -Chloroplasts are sites of photosynthesis -Golgi Bodies sends things around the cell -Vacuoles store food

2-10: A negative feedback loop maintains homeostasis by returning a changing condition back to it’s target set point. Describe how endotherms respond to changes in temperature and maintain homeostasis (a constant internal body temperature) How do endotherms respond to an increase in internal temperature? How do endotherms respond to a decrease in internal temperature?

2-10: A negative feedback loop maintains homeostasis by returning a changing condition back to it’s target set point. Describe how endotherms respond to changes in temperature and maintain homeostasis (a constant internal body temperature) How do endotherms respond to an increase in internal temperature? In response to cold many warm-blooded animals also reduce blood flow to the skin How do endotherms respond to a decrease in internal temperature? In response to warmth many warm-blooded animals also increase blood flow to the skin

2-11: Describe the 2 types of specific immune responses in mammals. HumoralCell-mediated What happens with a second exposure?

Thermoregulation Endotherms; isometric contraction of skeletal muscle (shivering) transfer mechanical heat to the body core while vasoconstriction of peripheral vassals reduces heat loss. When temperature increase they use evaporative cooling through sweating/ panting. Metabolism; the smaller the organism, the higher the metabolic rate