Nutrients & Biochem

1. Nutrients & Biochem

2. Definition of Homeostasis homeo = same; stasis = standing Homeostasis is the term we use to describe the constant state of the internal environment. Homeostasis is a state of balance in the body. The processes and activities that help to maintain homeostasis are referred to as homeostatic mechanisms.

3. THINK! You are exposed to ever changing environmental conditions. For example, you may walk out of an air conditioned room into the hot summer sun. How do you feel? What does your body do to adjust? How many other examples of homeostasis can you think of? For each of your examples, what would happen to you if you could not maintain homeostasis?

4. A Temperature Control System To help us understand homeostasis in living organisms, let us first look at a non-living system. We will use a temperature control system for a room which has many similar features to homeostatic mechanisms…. homeostasis animation-temperature control homeostasis animation

5. A Review Example: thermostatic heating system in a home Components of an automatic control system Variable is the characteristic of the internal environment that is controlled by this mechanism (internal temp in this example). Sensor (receptor) detects changes in variable and feeds that information back to the integrator (control center) (thermometer in this example).

6. Example Continued Integrator (control center) integrates (puts together) data from sensor and stored "setpoint" data (thermostat in this example). Set point is the "ideal" or "normal" value of the variable that is previously "set" or "stored" in memory. Effector is the mechanism (furnace in this example) that has an "effect" on the variable (internal temperature in this example).

7. Human Example of Negative Feedback Human example: shivering in response to cooling of body during cold weather or sweating when their core temperature gets too hot. Homeostasis allows an organism to remain in balance with its environment. If homeostasis is not maintained, it can harm or kill the organism.

8. High-wire Artist Model

9. Biochemistry The study of reactions and molecules which react to ensure life. Organic compound : molecule that contains a significant amount of carbon C (except CO, CO2, and CO3) or hydrocarbon groups. Molecules which have a “skeleton” of carbon and form an important part of living cells.

10. Essential nutrients • Fall under two categories: • Macronutrients • Micronutrients.

11. Macronutrients • large complex organic molecules that must be digested by an organism in order to be used. There are 4 macronutrients: carbohydrates, proteins, fats, nucleic acids (nucleic acids will be studied in detail in grade 12).

12. Micronutrients • small, simple substances that do NOT need to be digested by an organism in order to be used. These molecules are already small enough to diffuse across a plasma membrane. There are 3 micronutrients: minerals, vitamins & water

13. 1. Carbohydrates • Role :structural compounds and as energy reserves to fuel life processes - short and long term. (original source of energy) • Composed of the elements C, H and O in a 1:2:1 ratio. Empirical formula is Cm(H2O)n

14. Carbohydrates (Structure) Subunit (monomer)= Monosaccharide or simple sugar : Formed of 3 to 7 atoms of carbon. ex : glucose (primary energy source for cells), fructose (found in some fruit, semen), galactose (not normally found in nature). • Disaccharide or double sugar: 2 simple sugars together. Ex : sucrose (table sugar) = glucose + fructose, maltose = glucose + glucose, Lactose (in dairy) = glucose + galactose • Polysaccharide (AKA complex carbohydrates): many simple sugars together. Ex : starch (energy storage in plants), glycogen (energy storage in animals), cellulose (makes up the cell walls of plants). • saccharide and the suffix ose refer to sugar. i.e. glucose or monosaccharide.

15. Monosaccharide (Monomer) Disaccharide Polysaccharide (Polymer)

16. 2. Lipids • Roles : stores nutritive substances and energy long-term (2,25 times more energy than carbohydrates), insulation and protections of organs, makes hormones et and structural component of the cell membrane. • includes fats and oils, waxes, phospholipids, steroids, and some other related compounds.

17. Lipids (Structure) Sub unit (monomer)= Glycerol group + 3 fatty acids • Fatty acids can be long, short, saturated (solid), or unsaturated (often liquid). • All Lipids are hydrophobic (don’t mix with water). Consist of carbon, hydrogen and oxygen • Lipids with fatty acids Triglycerides (Fats and oils) Phospholipids Waxes • Lipids without fatty acids Steroids

18. Lipids (Triglycerides) • Fats (solid at room temperature) and oils (liquid at room temperature) are triglycerides.

19. Steroids (Sterols) Compact hydrophobic molecules containing fourfused hydrocarbon rings Examples: Cholesterol-precursor to sex hormones and vitamin D Sexhormones

21. Proteins Where do we find Proteins? What do gelatindesserts, hair, antibodies, spider webs, blood clots, egg whites, tofu, and fingernails all have in common? They are all made of protein.

22. 3. Proteins Roles : • Makes enzymes which facilitate chemical reactions. • Aids transport of substances across the cell membrane or in the blood. • Chemical messengers (hormones), like insulin. • The majority of cellular components are made of proteins. Ex: keratin (hair & nails), bone, muscle, tendon, ligament, amylase (enzyme), haemoglobin, etc.

23. Proteins (Structure) Sub unit (monomer)= Amino acids • Ex : amino acid + amino acid + a.a. + a.a. +... = protein • Amino acids form polypeptides which form proteins. • There are 20 a.a., but only 8 a.a. essential (we cannot produce them, must consume them)

24. Amino acids > Proteins (Monomer) (Monomer) (Monomer) (Polymer)

25. The Peptide Bond A polypeptide is many peptides joined together Amino acids are bonded together by peptide bonds. So two amino acids bonded together form a dipeptide. Many amino acids bonded together form a polypeptide.

26. Complex protein

27. 4. Nucleic acids • Roles : manage growth and development of all living forms through a chemical code. Determines characteristics and function of each cell (genetic code). Ex: DNA, RNA

28. Nucleic acids (Structure) Sub unit (monomer)= Nucleotides which are formed of a phosphate group, sugar (ribose or deoxyribose) and a nitrogen base. Ex: • RNA: single strand of nucleotides which contain ribose. • DNA: double strand of nucleotides which contain deoxyribose.

29. Nucleic acids There are 5 nitrogen bases: • Adenine • Guanine • Cytosine • Thymine • Uracil

30. Nucleic acid Nucleotide – sub unit or monomer of a nucleic acid

32. Covalent Bonds: Polar & Non-Polar A covalent bond is when two atoms share electrons. This sharing holds then together. Some atoms hold onto their atoms more tightly than others that is they are more electronegative. The relative electronegativities of the two atoms thatform a covalent bond determine whether or not a bond is polar or non-polar.

33. Polar Molecules H2O: two hydrogen atoms connected to an oxygen atom by single covalent bonds. Oxygen is more electronegative than hydrogen (oxygen has a stronger attraction for the electrons of a covalent bond), so the electrons of the polar bonds spend more time closer to the oxygen atom. This polar bond is a result of the uneven sharing of electrons. In other words, the bonds that hold together the atoms in a water molecule are polar covalent bonds. The water molecule is a polar molecule, meaning the ends of the molecule have opposite partial charges.

34. Structure of water The oxygen end of the molecule has a partial negative charge, and the hydrogens have a partial positive charge

35. Hydrolysis Process by which a large polymers or macromolecules is cut into monomers with the addition of water. Hydro= water So: Hydrolyse = cut Lyse = cut with water

36. Condensation or dehydration synthesis Process by which monomers attach together to form large polymers or macromolecules, with the loss of a water molecule.

37. Bibliography • http://www3.ntu.edu.sg/home/CXGuo/Eatingright_files/main_files/image003.jpg • http://www.synfusion.com/Expertise/Molecules_and_Integration.JPG • http://academic.brooklyn.cuny.edu/biology/bio4fv/page/1-6branch2.JPG • http://lc.brooklyn.cuny.edu/smarttutor/core3_21/images/macro/2b.2.glucose.gif • http://www.chm.bris.ac.uk/motm/glucose/sucrose.gif • http://img4.cookinglight.com/i/2008/04/fats-types-0804p106-m.jpg • http://www.realfitnessblog.com/wp-content/uploads/2008/11/fat_f2.jpg • http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20101/Bio%20101%20Lectures/Biochemistry/glycerol,%20fatty%20acids,%20triglyceride.gif • http://graphics8.nytimes.com/images/2007/08/01/health/adam/19823.jpg • http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/Tripeptide.gif • http://www.ks.uiuc.edu/images/ofmonth/2006-04a/secyh_big.png • http://ludwig-sun1.unil.ch/~vjongene/molbio/pics/amp.jpg • http://creationwiki.org/pool/images/b/b9/Nucleotides.png • http://media-2.web.britannica.com/eb-media/64/47664-004-7088EE3D.jpg • http://www.ustboniface.mb.ca/cusb/abernier/Biologie/Module1/Images/reactioncondensation.jpg • http://library.thinkquest.org/28751/media/review/figure/peptide.gif • http://porpax.bio.miami.edu/~cmallery/150/protein/c8.8x13.hydrolysis.sucrose.jpg