Answer to Question #198087 in Biochemistry for Paul Hackman

Question

11. Indicate which type of bonds are involved in the following

a. Formation of the primary structure of a protein

b. Stabilization of the alpha helix and beta pleated sheet structures of proteins

12.Identify the biomolecular composition of the following cells

a.Endoplasmic reticulum

b.Mitochondria

c.Cytoskeleton

d. Nucleus

13 Under aerobic catabolism of glucose ,in which compartment of the eukaryotic cell does the following reaction occurs?

a conversion of pyruvate to acetyl CoA

b.conversion of succinyl -CoA to succinate

c.conversion ofNADH to ATP.

d.conversion of phosphologlycerate to phosphoenolpyruvate.

14. Briefly outline how ATP is generated from glucose in the absence of oxygen. What is the importance of this pathway?

15. Briefly explain the process by which excess dietary carbohydrates and lipids are stored in the human body

Answer 1

11a) peptide Bond

11b) Hydrogen Bond

12)Biomolecules compostion of A)Edoplasmic Reticulum is the transport network for molecules targeted for certain modifications and specific destination, as compared to molecules that will float freely in the cytoplasm

B)Mitochondria consist of two membrane and provide the metabolic transformation of carbohydrate, lipids, amino acids and other metabolic compounds resulting in the production of ATP

C)Cytoskeleton: acts to organize and maintain the cell's shape , anchors organelles in place , helps during endocytosis, the uptake of external materials by a cell and cytokinesis

D)Nucleus is the most conspicuos organelle found in a Eukaryotic cell. It houses the cell's chromosomes and and is the place where almost all DNA replication and RNA Synthesis occurs

13) a.) mitochondrial matrix

b) mitochondrial matrix

c) inner mitonchondrial membrane

d) Cytosol(cytoplasm)

14) Glycolysis occurs in the cytoplasm where one 6 carbon molecule of glucose is oxidized to generate two 3 carbon molecules of pyruvate. The fate of pyruvate depends on the presence or absence of mitochondria and oxygen in the cells. The electron transport chain is the major site of oxygen consumption and the generation of ATP in the mitochondria. In cells with mitochondria, the pyruvate is decarboxylated by pyruvate dehydrogenase complex to form Acetyl-CoA that feeds into the Tricarboxylic acid cycle and ultimately participates in ATP production.During the absence of oxygen (anaerobic conditions) and in the cells lacking mitochondria, anaerobic glycolysis prevails. The pyruvate is reduced to lactate as NADH is reoxidized to NAD+ by lactate dehydrogenase. This process is an important source of ATP for cells that lack mitochondria such as erythrocytes. During aerobic glycolysis, this NADH is transported by the malate aspartate shuttle or glycerol phosphate shuttle to the mitochondria where it is reoxidized to NAD+ while it participates in the electron transport chain to produce ATP[1][2].

15) The excess energy from the food we eat is digested and incorporated into adipose tissue, or fatty tissue. Most of the energy required by the human body is provided by carbohydrates and lipids. As discussed in the Carbohydrates chapter, glucose is stored in the body as glycogen. While glycogen provides a ready source of energy, lipids primarily function as an energy reserve. As you may recall, glycogen is quite bulky with heavy water content, thus the body cannot store too much for long. Alternatively, fats are packed together tightly without water and store far greater amounts of energy in a reduced space. A fat gram is densely concentrated with energy—it contains more than double the amount of energy than a gram of carbohydrate. Energy is needed to power the muscles for all the physical work and play an average person or child engages in. For instance, the stored energy in muscles propels an athlete down the track, spurs a dancer’s legs to showcase the latest fancy steps, and keeps all the moving parts of the body functioning smoothly.

Unlike other body cells that can store fat in limited supplies, fat cells are specialized for fat storage and are able to expand almost indefinitely in size. An overabundance of adipose tissue can result in undue stress on the body and can be detrimental to your health. A serious impact of excess fat is the accumulation of too much cholesterol in the arterial wall, which can thicken the walls of arteries and lead to cardiovascular disease. Thus, while some body fat is critical to our survival and good health, in large quantities it can be a deterrent to maintaining good health.

And Carbohydrate =>One of the primary

functions of carbohydrates is to provide your body with energy. Your cells

convert carbohydrates into the fuel molecule ATP through a process called

cellular respiration.