Download Proteins…

Proteins…
► Let’s
Review…… then…..
► Let’s discover proteins….
► PollEv.com/tinalambiase209
Functions of Proteins …
►
Enzymes – reduces activation energy
 Ex: amylase – helps to digest amylose

ATP synthase – helps to make ATP
Structural Proteins – provide support
ex: elastin, horn, silk (web), keratin (hair &
nails)
Movement – actin and myosin muscles
Defense – antibodies in bloodstream
Storage – albumin in egg whites
Signaling – growth hormones in bloodstream
What do you think is happening to
the proteins within these eggs????
►!
Proteins
►C,
H, O, N and sometimes S
►Made in ribosomes
►Cell membranes
►Hormones (insulin)
►Hemoglobin
►Enzymes (control the rate of
reactions)
Building Blocks of Proteins
Amino Acids
►Amino
Group –
NH2
►Carboxyl
group –COOH
►Variable group
–R
Dehydration Synthesis of
Proteins
► Removal
of a water molecule from
amino acids to make proteins.
 Dipeptide – two amino acids together
 Tripeptide – three amino acids
together
 Polypeptide – more than three amino
acids together
All linked together with “Peptide
Bonds”
Dehydration Synthesis of
Proteins
►
Amino Acid + Amino Acid -- Dipeptide + Water
Removing the water
molecule
► Producing
a peptide bond
Dehydration Synthesis of Proteins
Dipeptide
►Locate
your peptide bond!!!
Can you draw a peptide bond?
►Which
two functional groups
join to make the peptide
bond???
How do we break proteins down??
HYDROLYSIS
►Add
the water molecule back in to
replace the peptide bond
►Put the amino acids back to the way they
were!!!
►Each amino acid must have an amino
group –NH2 and a carboxyl group -COOH
Hydrolysis
► Dipeptide
+ water = amino acid +
amino acid
► Tripeptide
+ 2 water molecules =
amino acid + amino acid + amino acid
►NOW
YOU TRY……
Hydrolysis of Proteins
Hydrolysis is the OPPOSITE
of dehydration synthesis
►What
reaction is this?
►Can you locate the peptide bond?