proteins name__________ dietary sources of proteins fish, meat, nuts, beans, dairy products, some...
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Proteins Name__________
Dietary Sources of Proteins
Fish, meat, nuts, beans, dairy products, some whole grains are high in protein
2006-2007
Proteins: Multipurpose molecules•Vary widely in their size, shape, structure and function•Contain C, H, O, N •Organic•Although 70% of your body is made of water, most of the other 30% is protein.
Proteins Many functions:
signallingHormones are chemical signals from one body
system to another Ex) Insulin movement
Muscle proteins can contract (squeeze) protection
Antibodies (immune system) protect against germs
chemical reactions in the body (metabolism)Enzymes help to speed up chemical reactions
Can be used as an energy source but only as a last choice if no carbs or lipids are available.
collagen (skin)
Proteins
insulin
Examples muscle skin, hair, fingernails, claws
collagen, keratin
pepsin digestive enzyme
in stomach
insulin hormone that controls blood
sugar levels
pepsin
Proteins Building block (monomer) = amino acids
20 different amino acids exist Plants can make all of them Your body can only make some and
must get others from foodThere’s
20 of us…like 20 different
letters in analphabet!
Can make lots of different
words
Examples of Amino Acids
Amino acid chain = polypeptide
A lot of variety in proteins because each amino acid has a different R group.
amino acid amino acid amino acid amino acid amino acid
Polypeptide = polymer Contains many amino acids bonded
together by dehydration synthesis
Amino Acids bond to form a polypeptide which folds to become a protein
Peptide Bond = covalent bond between two amino acids
Remember:Dehydration Synthesis
joins monomers!
Remember:Hydrolysis breaks up polymers!
Peptide bond
Polypeptide ExampleThis one contains 6 amino acids.
Alanine Glycine Tyrosine Glutamic Valine Serine Acid
Folding Protein = a properly folded polypeptide
A protein cannot do its job until its properly FOLDED.
Chain coil fold sometimes join
multiple chains
pepsin
For proteins: SHAPE matters!
collagen
Proteins fold & twist into 3-D shape that’s what happens in the cell!
Different shapes = different jobs
hemoglobingrowth
hormone
It’s SHAPE that matters! Proteins do their jobs, because
of their shape Unfolding a protein destroys its shape
wrong shape = can’t do its job unfolding proteins = “denature”
High temperature Extremes in pH (acidity)
folded
unfolded“denatured”