Lipids
What is a lipid? What are the functions? What are the types of lipids?
Large non-polar molecule that is insoluble in water
Long-term energy storage, Protection/insulation, Structural components
Triglycerides, Phospholipids, Steroids
Where are amino acids found?
20 different ones found in proteins in body, but 8 have to come from diet
When can a protein not function properly? What is this called?
unless they fold into their proper shape
loses shape- denatured (destroys protein function)
Define Biomolecules and the 4 goups that they are categorized into
most molecules that make up the body
groups- Carbohydrates, Proteins, Nucleic Acids, Lipids
What has to be present for a reaction to occur?
Activation Energy
Define Tryglycerides. List the Functions. What is the composition of a triglyceride?
Fats and oils
Long-term energy storage and insulation
1 glycerol molecule linked to 3 fatty acids
Why do 8 amino acids have to come from diet?
Humans cannot synthesize
What disrupts protein structure?
Exposure of proteins to certain chemicals, change in pH, or high temperature
Describe polymers and monomers
Polymers- long chaina of repeated units
Monomers- individual units that make up polymers
What do enzymes end with and what is an example?
end in "-ase" (ex. sucrase- breaks sucrase down into glucose and fructose)
What is the difference between unsaturated, saturated, and trans fat?
Unsaturated- double bonds between carbons in fatty acid tails (Liquid at room temp., pack looser: Plant oils)
Saturated- no double bonds between carbons in fatty acid tails (solido at room temp, pack dense: Butter)
Trans Fat- lab converted cis-fatty acid to trans-fatty acid so it is better for cooking, have longer shelpf life. Problem- enzymes don't break down trans-fat quickly so leads to more plaque in arteries
How do amino acids differ?
By their R (radical) Groups
What are the 4 levels of proteins?
Primary, Secondary, Tertiary, Quaternary
Describe Dehydration Synthesis and Hydrolysis.
Hydrolysis- breaking of a covalent bond, water molecule is used (breaks polymers to make monomers)
What are enzymes?
proteins that speed up reactions by holding substrates and stressing certain chemical bonds; not used up in a reaction and reused
What is the structure and function of a phospholipid?
Structure- similar to triglycerides (1 glycerol molecule, 2 fatty acids, 1 modified phosphate group), Fatty acids are nonpolar and hydrophobic, modified phosphate group is polar and hydrophylic
Function- form plasma membranes, in water form lipid bilayer (heads toward water and tails away from water)
Are R groups hydrophobic or hydrophilic?
Some are hydrophobic and some are hydrophilic
Describe the 4 levels of proteins?
Primary- The sequence of amino acids
Secondary- Characterizes by the presence of alpha felices and beta (pleated) sheets held with hydrogen bonds
Tertiary- Final overall 3-D shape of a single polypeptide; Stabilized by covalent, ionic, & hydrogen bonding and Van der Waals attractions between different areas of the polypeptide; Some reversible changes possible here...important!!
Quaternary- A unique shape formed by the coming together of several different polypeptides
Differentiate between monosaccharides, disaccharides, and polysaccharides
Monosaccharides- single sugar molecule
Disaccharide- 2 monosaccharides joined together by dehydration synthesis (ex. lactose is componed of 1 galactose and 1 glucose)
Polysaccharide- long chains of monosaccharides linked together; excellent energy storage because it is too big and tightly coiled and don't leak through membranas as quickly
What is an active site? What is induced fit?
Unique pocket that only fits one substrate; binds with substrate (reactants) to form enzyme-substrate complex
After substrate binds, active site "closes down" around it (handshake)
Describe Steroids and Cholesterol.
Composed of 4 fused carbon rings; functional groups define different esteroides (ex. testosterone, estrogen, progesterone, cortisol)
Cholesterol- precursor molécula for many steroids
How do you categorize an R group?
It can be polar, non-polar, really polar, really non-polar
What are the 6 Functions of proteins and examples
Structure- keratin, collagen
Communication- some hormones, receptors
Membrane Transport- Channel proteins, carrier proteins
Recognition- Glycoproteins
Movement- Actin/ Myosin, Flagella, Cilia
Enzymes
Define and describe a protein
Definition- polymers of amino acids linked together by peptide bonds (long chains are called polypeptides)
Description-polypeptide that has folded into a particular shape and has a función
What are multienzyme complexes?
Each type of enzyme only does one thing so different enzymes group together to make the product easily pass to the active site of the next