Assignment Two: Nutrition & Cells Practice Questions

Nutrition & Cells Practice Questions

1. There are many differences between vitamins and minerals. First off vitamins are defined as small organic molecules and most vitamins are co-enzymes. Vitamins are water-soluble as well as fat-soluble. The water soluble vitamins include all B and C vitamins and tend to seep out of boiled vegetables as well as excreted through urine. The fat soluble vitamins are stored in fat and are not as easily released from the body and can be extremely toxic in high concentrations. All the fat soluble vitamins include vitamin A,D.E and K. Minerals are not organic like vitamins but are actually small in-organic molecules that also happen to be simple ions. Minerals are water-soluble and unlike vitamins do not happen to be fat-soluble.

2. Free radicals are highly reactive molecules that are left over from natural metabolic processes or simply come from the eviornment. Free radicals can cause damage to a human beings DNA that can eventually lead to cancer. The body can protect itself from free radicals by the consumption of antioxidants which can intercept and neutralize the radicals.

3. Essential Amino Acids are acids that can be consumed from food intake and most animal meat or animal protein which contains all of the essential amino acids needed for nutrition. Essential fatty acids are acids that cannot be synthesized by cells and belong to two families: Omega-3 and Omega-6. Essential fatty acids are involved mostly just in biological processes and not in energy storage.

4. Hydrogenation is when unsaturated fats plus hydrogen gas with addes pressure equals out to saturated fats. Hydrogenation affects the chemical structure of fats by causing trans-fats to form an unnatural conformation which is synthesized via hydrogenation itself, this in turn creates a clogging of the arteries and raises bad cholesterol.

5. Bacteria when used with a cap;ital 'B' refers to a domain name, thus Bacteria with a lower case 'b' refers to a term used with "Prokaryotes".

6. The organelles that are found in all cells are as follows:

The Plasama membrane, Nucleus(Chromatin-DNA, Nucleolus, Nuclear Envelope), Ribosomes, Rough ER, Smooth ER, Golgi Apparatus, Centrioles, Mitochondria, Cytoskeleton, Vesicles, Peroxisomes, Lysomes and small Vacuoles.

7. A concentration gradient is the action of diffusion that includes passive and active transport.The role that it plays in Osmosis is that it diffuses water through the action of active transport which is the movement of molecules from low concentration to high concentrations. Active transport also requires energy or ATP. Facillitates diffusion is also know as "Passive transport" and brings a net movement of molecules from high concentration to lower concentration until they reach equilibrium.

8. Cellular respiration occurs in Prokaryotes across the plasma membrane and in the mitochondria of eukaryotic cells.

9. The components found in both Prokaryotic cells and Eukaryotic cells that have different structural characteristics are the following:

Plasma Membrane: which in Eukaryotic cells have internal organells composed of lipid bilayer membranes.

Cytoplasm: which consists mostly of water and is fluid that fills the cells and surrounds the organelles.

DNA: DNA in prokaryotic cells happens to be linear or cirular in shape and is contained in the nuclear region. DNA in Eukaryotic cells is much longer and coils around the histone proteins. The DNA is always linear in shape and is contained in the nucleus, DNA in the eukaryotic cell is also known as chromatin when it is "relaxed" and as chromosomes when it is supercoiled.

Ribosomes: float freely in the cytoplasm of both Prokaryotic and Eukaryotic cells.

10. Proteins, Ribosomes and lipids are all manufactured in the Cytoplasm.

11. The three types of Endocytosis are as follows:

1. Phagocytosis: which has a plasma membrane, a phagosome(which is also
knows as a food vacuole) as well as a solid particle.

2. Pinocytosis: which has extracellular fluid, a vesicle and cytoplasm.

3. Receptor Mediated Endocytosis: which has a receptor, a coated pit, a
protein and coated vesicle.

12. Three cellular components that contain microtubules are:

13. The endosymbiotic theory is the theory in which mitochondria and chloroplasts are the results of years of evoution that is initiated by the endocytosis of bacteria which instead of becoming digested became symbiotic.

14. Mitochondria and Chloroplasts have in common that they both contain their own DNA and ribosomes. The ways in which they differ are that Mitochondria breaks down glucose using oxygen to produce energy for a cell, this process is also called: cellular respiration. Chloroplasts use light energy to convert atoms into water as well as CO2 into sugars and starches. Chloroplasts also have a double membrane and conatin Grana, Stroma and Chlorophyll.

15. The difference between lysomes and peroxisomes are that lysomes contain digestive enzymes and fuse with vacuoles that conatain food. Lysomes also cell refuse and capture bacteria. Peroxisomes are found in animal cells, and plant cells. In animal cells they are full of enzymes that oxidize amino acids. In plant cells they are full of enzymes that oxidize fat. In both the animal and plant cells they convert hydrogen peroxide into water.

16. Bacterial DNA differs from Eukaryotic DNA by


17. The two prokaryotic cell components that help bacteria cling to surfaces are the slime layer and the fimbria.