Midterm 1: Nutrients (proteins, carbs, lipids) Flashcards
Name 6 functions of proteins:
antibody enzyme messenger receptor structural component transport/storage
What are antibodies?
proteins that bind to foreign particles (like viruses and bacteria); help protect the body (EX: IgG)
What are enzymes?
proteins that carry out chemical reactions that take place in cells (ex: ATPase)
What are messenger proteins?
proteins that transmit signals to coordinate biological processes between different cells, tissues, and organs (ex: Growth factor hormone)
What are receptor proteins?
proteins that bind to messengers (ex: G-coupled protein receptor)
What are structural components of proteins?
proteins that provide structure and support to cells–also allow the body to move (ex: collagen)
What are transport/storage proteins?
bind and carry atoms/small molecules within cells and throughout the body (ex: hemoglobin)
What are proteins made up of?
amino acids
How many different types of amino acids are there?
20
What does EVERY protein contain?
a hydrogen amino functional group carboxyl functional group R group (side chain)
What determines the chemical behavior of a molecule?
the reactive part of the molecule
What type of reactions have to occur to form long peptide/polypeptide chains?
condensation (loss of a molecule when two come together)/dehydration (subset- loss of a water molecule) reactions
Name the type of bonds that form between the carboxyl group and the amino group (of amino acids):
peptide bond
T/F a peptide bond is covalent.
True
N-terminus
C-terminus
What do these terms mean?
N–amino terminus
C–carboxyl terminus
What is a hydrolysis reaction?
break the peptide bond and ADD water
What is a condensation reaction?
create a peptide bond and LOSE water
What is a primary structure?
peptide bonds between amino acids–has a structural backbone with R groups extending from it–has directionality bc of the N and C-terminus
*just a sequence of amino acids linked by the peptide bonds
Name the type of bonds that form between the carbonyl oxygen and the amide hydrogen of the polypeptide backbone.
hydrogen bonds
What are two common structures that occur in secondary structures?
alpha helices and beta pleated sheets (antiparallel configuration)
*just interactions between the backbones of that cause folding (the hydrogen bonds stabilize these structures)
What are tertiary structures?
interactions between R-groups of the polypeptide chains (3D shape)
What type of interactions happen between R-groups of polypeptide chains in tertiary structures?
hydrogen bonds ionic bonds van der waals interactions hydrophobic interactions disulfide bridges (in extracellular space)
What are Quaternary structures?
Interactions between multiple polypeptide chains.
What type if interactions are seen with Quaternary structures?
hydrogen bonds
ionic bonds
van der waals interactions
hydrophobic interactions
What is the name of
2 polypeptides?
4 polypeptides?
2 subunits= Dimer
4 subunits= Tetramer
*Quaternary structures
Name the two groups that tertiary/quaternary structures are grouped into.
Fibrous and Globular
What are proteins?
one or more polypeptides
Describe fibrous proteins.
elongated structures
insoluble in water
have structural roles
EX: collagen and elastin
Describe Globular proteins.
compact/spherical
surface IS water soluble/interior is insoluble
roles other than structural
EX: immunoglobulin, ATPase, Hemoglobin, enzymes
What is the primary function of carbohydrates?
provide the body with energy (ATP!!)
Explain the path of carbohydrates after ingesting them?
Carbs–> Glucose–> enters blood–> taken up into cells–> used to produce ATP
Name 3 of the functions of Carbs?
Provide the body with energy
Store energy
Promote good digestive health
What is the name of the storage form of glucose?
Glycogen
Indigestible carbs
DIETARY FIBER
What are some benefits of dietary fiber?
creates soft, bulky stool that moves easily through large intestine
helps delay absorption of other carbs–>helping prevent spikes in blood glucose levels
Name of the smaller units of carbs.
monosaccharides
What are the three components of monosaccharides?
carbon
hydrogen
oxygen
*one carbonyl group (R-C=O) and the remaining carbons each bear a hydroxyl (R-O-H) group
Name the different monosaccharides based on the different number of carbons: 3 4 5 6
3- triose
4- tetrose
5- pentose
6- hexose
What are the two carb names when the carbonyl group location varies?
Aldose
Ketose
Can hydroxyl group location vary?
YES
What reactions must occur to form disaccharides, oligosaccharides, polysaccharides, and monosaccharides?
Condensation Reactions (a water molecule is created (lost) during a glycosidic bond)
*Glycosidic bond (covalent bond) forms between a hydroxyl group of one molecule and the anomeric carbon carbon derived from the carbonyl carbon (the ketone or aldehyde functional group) of another
What type of structures do carbs form in an aqueous solution (chain, ring, etc.)?
ring structures
Name what consist of 2 monosaccharides.
Disaccharides
Sucrose
Glucose + Fructose
Lactose
Glucose + Galactose
Maltose
Glucose + Glucose
Name what consist of 3-12 monosaccharides.
Oligosaccharides
What are two examples of Oligosaccharides.
Immunoglobulin (in association with protein) and mucin
Where are Oligosaccharides primary located when covalently bonded to proteins?
on the surface of cells or in the ECM
Name what consist of greater than 12 monosaccharides.
Polysaccharides
Name some examples of polysaccharides.
Glycogen, starch, cellulose, glycosaminoglycan
Glycogen is compose of…
Composed of α-glucose monomers WITH extensive branching
Where is glycogen located?
Liver and Muscle
Starch is composed of…
Composed of α-glucose monomers with OR without branching
Name of branched starch.
amylose
Name of unbranched starch.
amylopectin
Storage form of glucose in animals
glucose
Storage form of glucose in plants
starch
Cellulose is composed of…
Composed of β-glucose monomers with NO branching
Can humans digest cellulose? Why?
No, because we have a lack of enzymes that are required to break down β-glucose linkages
what contributes to the formation of dietary fiber?
cellulose
Glycosaminoglycan (GAG) composed of…
Composed of repeating disaccharide units (amino sugar and uronic acid or galactose) without branching
Name the 5 GAGs
Chondroitin sulfate Keratan sulfate Dermatan sulfate Heparan sulfate Hyaluronate
Name the most abundant GAG
Chondroitin sulfate
Name the only GAG that is NOT sulfated
Hyaluronate
What type of charge do GAGs have?
highly negatively charges
What does the - charge do for GAGs?
attracts water
high lubricant/shock absorber due to high viscosity and low compressibility
Where are GAGs located?
on the surface of cells or in the ECM
T/F GAGs are linked to Core Protein (forming proteoglycans)
TRUE (exception: hyaluronate)
What is the main role of lipids?
reserve supply of energy (during periods of low food consumption–TAG can be broken down to produce energy)
Fatty Acids: function?
precursor to triglycerides; source of energy
Triglycerides: function?
energy storage; thermal insulator; filling space; binding organs together; cushioning organs
Phospholipids: function?
structural component of cell membranes; aid in fat digestion
Steroid hormones: function?
chemical messengers
Sphingolipids: function?
structural component (esp nerve cells); chemical messengers
Cholesterol (steroid): function?
component of cell membrane; precursor of other steroids
bile salts (steroid): function?
aid in digestion and nutrient absorption
fat soluble vitamins (A, D, E, K): function?
blood clotting, wound healing, vision, calcium absorption
Eicosanoids: function?
chemical messengers
Are lipids mostly hydrophillic or hydrophobic?
HYDROPHOBIC (mainly C, H, and some O)
How are lipids classified?
based on structure!
Name the three classification groups of lipids.
Simple lipids (esters of fatty acids) Complex lipids (esters + additional groups) Derived lipids (derived from hydrolysis of simple/complex lipids)
Name a simple lipid
triglycerides
Name 2 complex lipids
phospholipids
sphingolipids
Name 3 derived lipids
steroids (bile salts, steroid hormones, sterols)
Isoprenoids (vitamins: A, E, K, etc..)
Eicosanoids (prostaglandins, leukotienes, thromboxanes)
What is a fatty acid?
hydrocarbon chain with a carboxyl group at one end; even # of carbons (10-30)
Describe the difference between single and double bonds within a hydrocarbon chain:
Single bonds: SATURATED (with -H); linear
Double bonds: UNSATURATED (with less -H); bent
Describe Saturated fatty acid at room temp.
SOLID
Describe Unsaturated fatty acid at room temp.
LIQUID
What is the difference between a cis and trans unsaturated fatty acid?
Cis: 2-H’s attached to C=C on the SAME side (most naturally occurring)
Trans: 2-H’s attached to C=C on OPPOSITE sides
Why are trans fatty acids not recognized as “safe” by the FDA?
bc they are created in industrial processing by adding H to make the liquid more solid–thus making the hydrocarbon chain straight rather than bent
it increased individuals risk of heart disease, diabetes, and stroke
7,000-20,000 deaths could be eliminated per year by eliminating these from our diets
What is an ‘ester’ of a fatty acid?
Alcohol + fatty acid
Define alcohol (in terms of an ester lol)
contains hydroxyl groups attached to carbon
Name 2 examples of alcohols
glycerol and sphingosine
What makes up a triglyceride?
3 fatty acids + glycerol (alcohol)
storage form of fatty acids
What makes up a phospholipid (complex lipid)?
2 fatty acids + glycerol (alcohol) + phosphate + 1 polar group
Polar groups: ethanolamine, choline, serine, inositol
What makes up sphingolipids (complex lipid)?
fatty acid + sphingosine (alcohol) + 1 head group
Head groups: hydrogen (ceraminde), phosphocholine (sphingomyelin), sugar (glycolipid; 1 sugar- cerebroside, > 1 sugar- ganglioside)
Derived lipids posses the characteristics of:
lipids (hydrophobicity)
Name 3 derived lipids:
Steroids, isoprenoids, and eicosanoids
What makes up a steroid?
Steroid core + Side Chain
Steroid core (4 fused rings) Side chains make them unique
ex: sterols, steroid hormones, bile salts
What is the side chain of a sterol?
Hydroxyl
Name the most common sterol.
cholesterol
What is the most common steroid and what is it a precursor to?
Cholesterol and it is a precursor to bile salts and steroid hormones
Name some of the steroid hormones:
Mineralocorticoids (corticosterone; aldosterone) Glucocorticoids (cortisol) Progesterone Testosterone Estrogen Vitamin D
Are isoprenoids saturated or unsaturated?
Unsaturated
What is an example of an isoprenoid?
Fat-soluble vitamins
What are eicosanoids derived from?
arachidonic acid
What are some examples of eicosanoids?
prostaglandins, leukotrienes, thromboxanes
