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Basic Biochemistry
What is Biochemistry?
Biochemistry is the study of the chemical interactions of living things.
Biochemists study the structures and physical properties of biological molecules. Often are involved in the manufacture of new
drugs and medical treatments
Biochemistry: where chemistry and biology meet head-on
Living things require millions of chemical reactions within the body, just to survive.
Metabolism = all the chemical reactions occurring in the body.
Organic molecules: usually associated with living things. always contain CARBON. are “large” molecules, with many atoms always have covalent bonds (share electrons)
Composition of an Atom
Protons: Nucleus, positive charge Neutrons: Nucleus, no charge Electron: Energy levels, negative
charge
Isotopes
Atoms of the same element with a different number of neutrons.
Benefits: the radiation given off of some isotopes can be used to treat cancer and kill bacteria that cause food to spoil.
Can also be used as “tracers” to follow the movement of substances thru the body.
Bonding
There are 2 main types of bonds: Ionic: When atoms transfer
electrons Covalent: When atoms share
electrons
Acids & Bases
Acids have a pH of 0-6 Bases have a pH of 7-14 Neutral = 7 What is the optimal pH of human
blood? 7.4
Buffers
Substances that can absorb or release H+ as levels fluctuate within living systems to help maintain a constant pH
Example: Carbonic Acid Bicarbonate (buffer that helps maintain pH of the blood)
Macromolecules of Cells
Macro = large
4 types of macromolecules in cellular biology
1. Carbohydrates2. Lipids3. Proteins4. Nucleic Acids
Macromolecule #1: Carbohydrates
Sugars and groups of sugars
Purposes: energy and structure
Includes three types: Monosaccharide (1 sugar – quick energy) Disaccharide (2 sugars – short storage) Polysaccharide (many sugars – energy
long storage & form structures)
Macromolecule #1: Carbohydrates Polysaccharide Examples:
Glycogen—glucose polymer stored for future energy needs. Found in liver, muscle and sperm, etc.
Cellulose—glucose polymer used to form fibers for plant structures. Humans can’t digest (fiber). Most abundant organic molecule.
Chitin—glucose polymer for exoskeletons of some crustaceans & insects.
Polysaccharides
Polysaccharides
Macromolecule #2: Lipids
Insoluble in water (think oil & water)4 types:
1-triglycerides (fats & oils) (long-term energy storage, insulation)
2-phospholipids (primary component of cell membrane)
3-steroids (cell signaling) cholesterol molecules modified to form sex
hormones. (e.g. testosterone, estrogen, etc.) 4-waxes (protection, prevents water loss)
Used mainly by plants, but also bees, some furry animals and humans.
Triglycerides
Phospholipids
Steroids
Waxes
Macromolecule #3: Proteins
Probably the most complicated of all biological molecules.
Serve the most varied purposes, including:
Support structural proteins (e.g., keratin, collagen)
Enzymes speed up chemical reactions
Transport cell membranes channels, transporters in blood (e.g., Hemoglobin)
Defense antibodies of the immune system
Hormones cell signaling (e.g., insulin)
Motion contractile proteins (e.g., actin, myosin)
CollagenCollagen
Antibodies
Cellular Transport
actin & actin & myosin fibers myosin fibers
in musclesin muscles
Motion
Macromolecule #3: Proteins
The building blocks of proteins are AMINO ACIDS. There are only 20 types of Amino Acids.
There are millions of different proteins, and they are all built from different combinations of the 20 amino acids.
Amino acids join together to form peptides, polypeptides, and polypeptide chains.
Enzymes
Act as a lock and key Specific: One substrate fits one
enzyme Reusable: One enzyme can break
down many substrates
Competitive Inhibition
In competitive inhibition, the inhibitor binds to the same active site as the normal enzyme substrate, without undergoing a reaction.
Induced Fit Model
In this model, the enzyme changes shape on substrate binding. The active site forms a shape complementary to the substrate only after the substrate has been bound
Macromolecule #4: Nucleic Acids
Nucleotides: building blocks of nucleic acids. Each nucleotide contains
(a) phosphate molecule, (b) nitrogenous base, and (c) 5-carbon sugar
Several types of nucleic acids, including: DNA: deoxyribonucleic acid
Genetic material, double stranded helix RNA: ribonucleic acid
Genetic material, single stranded ATP: adenosine triphosphate
High energy compound
DNADNA
Nucleotide Structure
THE BIG PICTURETHE BIG PICTURE
Chemistry is essential for Chemistry is essential for life…life…
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