Carbon is the fundamental building block of all the organic compounds needed by living things, including nucleic acids, carbohydrates, proteins and fats. For example, Neisseria meningitidis ferments glucose and maltose, but not sucrose and lactose, while Neisseria gonorrhoea ferments glucose, but not maltose, sucrose or lactose
Cellular Respiration (Krebs Cycle)
Electron Transport System: a) consists of a series of enzymes on the inner mitochondrial membrane b) electrons are released from NADH and from FADH2 and as they are passed along the series of enzymes, they give up energy which is used to fuel a process called chemiosmosis, which drives the process of ATP synthesis using an enzyme called ATPase. Citric Acid or Krebs Cycle a)occurs in the inner mitochondrial matrix b) an aerobic process; will proceed only in the presence of O2 c) net yield of 2 ATP per glucose molecule d) net yield of 6 NADH and 2 FADH2 (NAD+ is reduced to NADH, FAD+ is reduced to FADH) e) in this stage of cellular respiration, the oxidation of glucose to CO2 is completed
Molecules derived from the breakdown of fats, proteins, and carbohydrates can enter glycolysis or the Krebs cycle at various points in order to yield more energy to an organism. Part A How does oxygen get into or out of chloro- plasts and mitochondria? Part B What are the roles of oxygen in the processes of photosynthesis and cellular respiration, and how are the roles similar? Make sure you get plenty of rest the night before the test
Mitochondria: The Aerobic Engines
A large body of research suggests that the enhancement of mitochondrial density in skeletal muscle is a key component in the development of performance in endurance sport. Recent research has begun to identify the signaling that initiates the chains of enzymatic reactions which turn on the combination of nuclear and mitochondrial genes responsible for mitochondrial biogenesis
This subject may not be covered in the lectures, but you are responsible for all of the information in these notes because it is important background for topics in this course, suchas muscle cell physiology (Chapter 7). When fats are being used as the primary energy source such as in starvation, fasting or untreated diabetes, an excess amount of acetyl CoA is produced, and is converted into acetone and ketone bodies
Photosynthesis 1
In the light reactions, excited electrons from chlorophyll flow through a cytochrome transport system along membranes of the thylakoid disks (thylakoid membranes). When the guard cells lose water pressure on a hot day, they deflate and push together, thus closing off the stoma and reducing water loss (transpiration) through the leaf
SparkNotes: SAT Subject Test: Biology: Cell Respiration
Alcoholic Fermentation Another route to NAD+ produces alcohol (ethanol) as a by-product: pyruvate + NADHethyl alcohol + NAD+ + CO2 Alcoholic fermentation is the source of ethyl alcohol present in wines and liquors. The Krebs cycle is called a cycle because one of the molecules it starts with, the four-carbon oxaloacetate, is regenerated by the end of the cycle to start the cycle over again
Fatty acids and amino acids when transported into the mitochondria are degraded into the two-carbon acetyl group on acetyl CoA, which then enters the Krebs cycle. These ATP molecules are formed when phosphate groups are removed from phosphorylated intermediate products of glycolysis and transferred to ADP, a process called substrate level phosphorylation (synthesis of ATP by direct transfer of a high-energy phosphate group from a molecule in a metabolic pathway to ADP)
IB Biology Notes - 8.1 Cell respiration
This energy is then used to pump protons (H+) from the matrix across the inner mitochondrial membrane and into the space between the inner and outer mitochondrial membranes. Since the electrons come from previous oxidation reactions of cell respiration and the ATP synthase catalyses the phosphorylation of ADP into ATP, this process is called oxidative phosphorylation
While many microorganisms can accomplish this task within their single cell, we larger macroorganisms have evolved body organs dedicated to efficiently obtaining enough oxygen -- and eliminating enough carbon dioxide -- to undergo enough aerobic respiration to fuel our large, complex selves. While photosynthesis takes place in the chloroplasts of plant and algae cells, aerobic respiration takes place in the cytoplasm (gooey inner cell space) and mitochondria of all eukaryotic cells
Pyruvate carboxylase is allosterically activated by high concentrations of acetyl CoA, which signal the need for more oxaloacetate to feed the TCA cycle. Racker demonstrates that the electron transport chain and the F0F1 ATP synthase are biochemically independent systems, coupled only by the proton motive force across the mitochondrial inner membrane
Although operating at opposite poles of the ETC activity spectrum, both conditions can lead to cell death through energy deprivation or ROS-triggered apoptosis. The communication system in higher organisms utilizes a battery of mechanisms such as hormonal regulation through the bloodstream, electrical conduction to transmit signals in neurons, and small molecules or ions inside the cell such as cAMP and calcium
Cell Respiration: Introduction
Since most textbooks provide abundant details of the chemical reactions in respiration, this tutorial will focus on how the chemical energy in glucose is converted into ATP and where respiration occurs in the cell. Carbohydrates, fats, and proteins can all be used as fuels in cellular respiration, but glucose is most commonly used as an example to examine the reactions and pathways involved
Aerobic Respiration - BIOLOGI MEDIA CENTRE
In eukaryotic cells, the electron transport chain and the enzyme ATP-synthase are embedded in the inner membrane of the mitochondrion in folds called cristae. Krebs cycle When pyruvic acid enters the mitochondrial matrix, it reacts with a molecule called coenzyme A to form acetyl coenzyme A, abbreviated acetyl CoA
Cellular Respiration
Because there are a number of enzymes and steps involved in forming porphyrin rings, there are a number of possible points in the process where genetic defects could occur. Out of many possible types of fermentation processes, two of the most common types are lactic acid fermentation and alcohol fermentation (other types of fermentation such as methanol fermentation and acetone fermentation also exist)
Aerobic Respiration
Citric acid cycle Each of the 2-carbon acetyl groups produced from the original glucose molecule is bonded to a pre-existing molecule of oxaloacetate to form citrate (i.e
Cellular Respiration
This has strengthened the theory that mitochondria are the evolutionary descendants of a bacterium that established an endosymbiotic relationship with the ancestors of eukaryotic cells early in the history of life on earth. (Defects in either process can produce serious, even fatal, illness.) The Outer Membrane The outer membrane contains many complexes of integral membrane proteins that form channels through which a variety of molecules and ions move in and out of the mitochondrion
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