Basic Chemistry, Lipids, Carbohydrates, and Proteins Biochemistry – 9/30

Overview Unit covers basic biochem (esp. proteins) and data analysis. Notes from last year – requested more “direct instruction”, less group work for basic biochem Plan: Today, tomorrow: discussion, notes, info Friday: Group verbal quiz

The Nature of Matter (2-1) Turn to your neighbor Discuss: “What do you know about atoms?” What are they made of? What do they look like? What else do you remember about them? Be ready to share Copy the diagram we develop on the board Atom: simplest unit of matter; cannot easily be broken down into electrons, neutrons, protons Fun fact (don’t need to memorize): You have about atoms in your body! 100,000,000,000,000,000,000,000,000,000

Atoms and molecules What is the difference between atoms and molecules? Educated guess! Discuss with neighbor, be ready to share Molecule: Two or more atoms chemically joined Function as a unit with new properties Can be split back apart into individual atoms Can be small (ex: water – only 3 atoms) Can be large (ex: table sugar has 45 atoms!) Volunteers! I need three of you, please

Elements and Compounds What are elements and compounds? Discuss with neighbor, be ready to share anything Element: material that has only ONE type of ATOM Ex: sodium Ex: chlorine Compound: material that contains only ONE type of MOLECULE. Ex: sodium chloride Remember: elements contain one type of atom Pure compounds contain one type of molecule I need 8 volunteers this time

Organic compounds Organic carbon compounds? Contain carbon atoms and are/were part of a living system “Building blocks” of all major organelles, tissues, organs, structures, etc. in living organisms Macromolecules? Really large organic compounds 4 main types? Lipids Carbohydrates Proteins Nucleic acids (DNA, RNA) Protein macromolecule

Lipids Include “oils” (liquids), “fats” (solids) Working with your lab group: Discuss HW from last night. Be ready to share at least three ways that lipids affect living organisms.

Lipids – why are they important?

Used to store lots of energy (fat) Fats more difficult to break down (metabolize), but store more energy than carbohydrates Form cell membranes ( the “skin” of the cell ) Phospholipids Cell communication Lipids on/in membrane Hormones Communication throughout body Insulation of nerve cells – myelin (lipid)

Lipids: what do they look like? Each molecule has a “head” with a “tail” Tail usually consists of two or three strands

Verbal Warmup – day 2 During lunch one day, you bump into a friendly MTHS student. It’s clear he’s studying for his Bio Chapter 2 exam, and looks stressed. He looks up at you and says, “Could you please explain the difference between the word ‘compound’ and the word ‘molecule’ to me?” What would you say? Discuss with your partner and be ready to share.

Carbohydrates Include: Monosaccharides (simple sugars) Examples: Fructose (honey, some fruits), Glucose Polysaccharides (monosaccharides joined together) Example: starch, sucrose, lactose Working with your lab group: Discuss HW from last night. Be ready to share at least three ways that carbohydrates can affect living organisms.

Carbs – why are they important?

Carbohydrates - why are they important? Glucose - main source of energy for cells. Plants make their own glucose How do animals obtain glucose? Animals ingest glucose in their food Glucose - and carbs in general- contain less energy than lipids, but are easier to metabolize (Blood sugar = glucose in blood)

Carbohydrates - monosaccharides Main ring of carbon and oxygen atoms C – O C C or C – C

Carbohydrates – polysaccharides Many monosaccharides combined = polysaccharide Plants store extra glucose as “starch” Ex: potatoes Glucose + Glucose + Glucose = Starch (straight chain) What does a lipid look like?

Carbohydrates – polysaccharides Animals store extra glucose as “glycogen” Stored in our liver and muscle cells Branching chain Difference between starch and glycogen?

Proteins – what are they? Are macromolecules made of amino acids joined together Working with your lab group: Discuss HW from last night. Be ready to share at least three ways that Proteins affect living organisms.

Proteins – why are they important?

Proteins Form muscles, bone, other important structures (determine what you look like!) Move materials in and out of cells Helps with immune responses Control the rate of chemical reactions (enzymes!)

Proteins – amino acids 20 amino acids exist in nature Humans can make 12 amino acids How do they get the others? Must ingest remaining 8 amino acids “Essential amino acids” Without, can’t build proteins needed for life How are DNA and proteins related? DNA builds proteins by organizing amino acids in your body (puts amino acids in order)

Proteins – what do they look like? Primary structure – the order of the amino acids

Proteins – what do they look like? Secondary and tertiary structure (folding) Secondary – initial folding Tertiary – more complex folding – into a molecule like this one Write down the marker analogy

Proteins and chemical reactions What is a chemical reaction? Discuss. Occurs when chemical(s) (reactants) react to form different chemicals (products) Example: glucose and oxygen react to form carbon dioxide and water Enzymes speed up chemical reactions in living organisms (cells) –millions of time faster! Enzymes “catalyze” reactions Example of how one thing could catalyze something else?

Proteins and enzymes Enzymes provide a site for chemicals to come together to react Kind of like a lock and key Enzymes are specific – only help certain chemicals react. (Animation – describe in notes)Animation

What affects enzymes reaction rates? Without enzymes, most reactions in cells would not happen quickly enough for life What affects the speed of enzyme reactions? pH (effect varies, but big changes slow enzymes) How much are produced by cells (more = faster) Mixing (better mixed usually = faster) Temperature (warmer usually = faster) Too warm = “denatured” (egg white) Denatured enzymes DO NOT FUNCTION Why are fevers a problem?

Amylase Amylase is an ENZYME that helps 1 starch molecule… …get broken down into 3 glucose molecules Without amylase, your body could not break down starch efficiently.