Test 3 Flashcards
What are lipids?
Organic compounds that contain C, H, and O
Do lipids have more hydrogen or less hydrogen that CHOs? More or less oxygen?
More
Less
How much more energy is in lipids than CHOs?
2.25 times more
How many calories should come from fat?
Less than 30%
What is the structure of lipids?
CH3(CH2)x–COOH
What part of lipids is polar?
Carboxylic acid (COOH)
What is a short chain lipid? Examples?
Less than 14 carbons
Acetate, Butyrate, Propionate
What is an example of a long chain lipid?
Fatty acid chains
What is a saturated fatty acid?
No double bond
What are fatty acids saturated with?
Hydrogen
What are some saturated fatty acids? What is the carbon to unsaturated points ratio for each?
Myristate: C14:0
Palmitate: C16:0
Stearate: C18:0
What is an unsaturated fatty acid?
It has pi bonds and loses 2 hydrogens
What are some unsaturated fatty acids? What is the carbon to unsaturated points ratio for each?
Palmitoleic: C16:1
Oleic: C18:1
Linoleic: C18:2
Linolenic: C18:3
Arachidonic: C20:4
What is an essential fatty acid?
Can’t be synthesized by body, therefore it is a dietary requirement
What are the essential fatty acids?
Linoleic
Linolenic
Arachidonic (cats)
What is triacylglycerol composed of?
Glycerol and 3 fatty acids
Look at the structure of triacylglycerol on page 54
Look at the structure of triacylglycerol on page 54
What do the following suffixes mean for fatty acids?
Di-
Mono-
Phospho-
Glyco-
Sulfo-
2 fatty acids
1 fatty acid
Phosphate group
Carbohydrate group
Sulfate group
What is a lipoprotein?
A lipid that contains protein (cholesterol)
What is a low density lipoprotein?
High in lipid, low in protein (bad cholesterol)
What is a high density lipoprotein?
Low in lipid, high in protein (good cholesterol)
What are waxes?
Esters of fatty acids and long chain alcohols that are not digestible
What are steroids like in water?
Insoluble in water
Look at the basic structure of a steroid on page 55
Look at the basic structure of a steroid on page 55
What is cholesterol?
Precursor for sex hormones
What are carotenoids? Example?
Vitamin A precursor
Carotene – yellow pigment of veggies
What is the goal of digestion in monogastric animals?
To turn triacylglycerol into monoglyceride and 2 fatty acids which are then absorbed
Triacylglycerol is insoluble and must become soluble
What are the 9 steps in digestion and absorption of monogastric animals?
- Course emulsion is formed (fat globule)
- Bile acts to form droplet in duodenum
- Lipase acts at fat:water interface and cleaves FA 1 and 3
- Micelles are formed
- Upon contact with microvilli in duodenum, monoglyceride and free fatty acids are absorbed
- As absorbed, monoglycerides and fatty acids are immediately resynthesized to triacylglycerol and phospholipids
- Triacylglycerol droplets enveloped by lipoprotein chylomicron and exits cells to lymph system
- Glycerol is passively absorbed
- Short chain fatty acids are absorbed without chylomicron and go to the blood. If fatty acid 2 is short chain, it goes to lymph
Look at page 59 under examples
Look at page 59 under examples
What happens to fatty acids in post absorption in monogastric animals?
Stored as fat in adipose tissue (constant turnover) Converted to acetyl CoA via β oxidation
Is β oxidation aerobic or anaerobic?
Aerobic–mitochondria
What is β oxidation?
Break down of fat to acetyl CoA
What is 1 cycle of β oxidation like?
- Takes off 2 carbons from acetyl CoA and gives 12 ATP
- 1 FADH2 (2 ATP)
- 1 NADH (3 ATP)
How many ATP does it take to activate β oxidation?
2
What is caproic acid’s carbon to unsaturated points ratio and formula?
C6:0 C6H12O2
How many times does caproic acid go through β oxidation?
2
How many ATP does caproic acid yield?
44
What is stearic acid’s carbon to unsaturated points ratio?
C18:0
How many times does stearic acid go through β oxidation?
8
How many ATP does stearic acid yield?
146
What can Acetyl CoA go to in ketosis?
Krebs, Acetoactetate (then acetone), and β-hydroxybutyrate
What are 4 clinical signs of ketosis?
High blood ketone level
High urine ketone level
Low blood glucose
Breath smells like acetone
What are 3 causes of ketosis?
Body is dependent upon gluconeogenesis (depletes oxaloacetate)
Body mobilizing stored fat (β oxidation –> increase acetyl CoA)
Acetyl CoA –> ketone bodies
When does ketosis occur?
Starvation
High producing dairy cow
Late pregnant ewe with twins or triplets
How can you treat ketosis?
Increase oxaloacetate precursors
What do the following oxaloacetate precursors become?
Propionate
Gultamate
Aspartate
Succinyl CoA
α-ketogutarate
Oxaloacetate
What is fatty acid synthesis similar to?
Reverse β oxidation
What happens in fatty acid synthesis with Acetyl CoA?
2 carbons are added to Acetyl CoA to get fatty acids
What is the first thing that enters fatty acid synthesis? What does the remaining stuff enter as?
Acetyl CoA
Malonyl CoA
How many carbons does Malonyl CoA have?
3
What is the basic idea of what happens in fatty acid synthesis? (In terms of the different CoA’s)
Malonyl CoA links to Acetyl CoA to get Acyl CoA
For every Malonyl CoA, how many ATP do you need? NADPH? What 2 other things are needed?
1
2
biotin and CO2
What is the reaction for palmitic acid?
8 Acetyl CoA + 7 ATP + 14 NADPH –> Palmitic acid + 8 CoASH + 14 NADP + 7 ADP (Biotin and CO2 over arrow)
Look at the reactions on page 62 of Acetyl CoA and Malonyl CoA
Look at the reactions on page 62 of Acetyl CoA and Malonyl CoA
How many carbons can a fatty acid have for the body to synthesize?
18 or less
What is the goal of fatty acid synthesis in ruminant animals?
To make triacylglycerol become 3 fatty acids and glycerol (propionate is absorbed)
In the rumen, what do free fatty acids attach to?
Fiber particles
What do free fatty acids do in the rumen?
Block cellulase from attacking β 1,4 bonds
What is the 5 step process of digestion and absorption in ruminant animals?
- TG is released from fiber particles in acid of abomasum
- Bile in duodenum
- Formation of micelle
- Absorbed
- Chylomicron goes to lymph (most absorbed fatty acids go to adipose)
What is the redox state of the rumen?
Highly reduced
What happens to unsaturated fatty acids in the rumen? What percentage does this happen to?
They become saturated
60%
What does 2/3 of fatty acids become in beef fat?
Stearic acid
What 3 fatty acids become stearic acid?
Linoleic
Linolenic
Oleic
How many different proteins are in the body?
about 100,000
How much of the body is protein on a dry fat free basis?
80%
What are the 3 functions of protein?
Structural (skeletal muscle, connective tissue, protective protein)
Specialized functions (enzymes, hormones, blood proteins)
Energy (AA converted to krebs cycle intermediates)
What is the composition of proteins?
Carbon, hydrogen, oxygen, and nitrogen. Some have sulfur and/or phosphorus
What does Kjeldahl N allow?
To measure nitrogen content
How do you find % crude protein?
% N x 6.25
What is true protein comprised of?
Amino acids
What do dietary amino acids become?
AA in intestinal lumen which become AA in blood which become tissue protein
Why do we eat protein?
Because our body needs amino acids
How many amino acids are we concerned with?
20
Look at the general structure of amino acids on page 65
Look at the general structure of amino acids on page 65
What is the most reactive part of the amino acid?
α carbon
What does the R group do on amino acids?
Gives individuality to the different amino acids
What are the 2 properties of amino acids?
Carboxyl group
Amino group
What kind of properties do carboxyl groups have?
Acid (donates H in solution)
What kind of properties do amino groups have?
Base (accepts H in solution)
How do you get an amino acid to act like an acid or base?
Dissolve it in neutral solution
What are the different chemical methods of classification?
Neutral
Acidic
Basic
Sulfur
Aromatic
What are the 9 neutral amino acids?
Glycine
Alanine
Valine
Leucine
Isoleucine
Serine
Threonine
Glutamine
Asparagine
What are the 2 acidic amino acids?
Aspartic Acid
Glutamic Acid
What are the 3 basic amino acids?
Histidine
Arginine
Lysine
What are the 3 sulfur containing amino acids?
Cysteine
Cystine
Methionine
What are the 3 aromatic amino acids?
Phenylalanine
Tyrosine
Tryptophan
What are essential amino acids?
Amino acids that can’t be synthesized by the body at a rate that can meet the body’s requirements. They are required in the diet
What are the 10 essential amino acids?
Phenylalanine
Valine
Threonine
Tryptophan
Isoleucine
Methionine
Histidine
Arginine
Leucine
Lysine
What are nonessential amino acids?
Can be synthesized by the body at an appreciable rate
What happened in the 1930s by Dr. Rose?
He was the first to classify essential and nonessential amino acids with his model of the growing rat
How many amino acids are required by ruminant animals?
None
What are peptides?
Covalent bonds that link amino acids between the –COOH of one amino acid to the NH3 of another
What is a dipeptide?
2 amino acids linked together
How long is a peptide?
Usually 3-8 amino acids long
How long is a polypeptide?
Longer than 8 amino acids
How much ATP does it cost to get peptide bonds?
4
What is the function of protein dependent on?
3D structure which is dependent on the sequence of amino acids
What determines the function of proteins?
Amino acids
What are disulfide bonds important for?
Maintaining protein structure
What are the terminal ends?
Glycine and Cysteine
What is glycine?
Amino terminal amino acid
What is cysteine?
Carboxyl terminal amino acid
What is the primary part of the structure of proteins?
The amino acid sequence
What does the secondary part of protein structure involve?
Bonding with disulfide bonds
What is the 3° part of the structure of proteins?
The 3D shape
What is the 3D shape of proteins caused by?
Hydrophobic amino acids
Hydrophilic amino acids
What types of amino acids are hydrophobic?
Neutral and aromatic
What types of amino acids are hydrophilic?
Acid and base
Where in the protein do hydrophobic amino acids go?
Inside
Where in the protein do hydrophilic amino acids go?
Outside
What is denaturing?
Irreversible unfolding of protein
What are the methods of denaturing?
Heat
Chemical
Decrease pH (HCl)
What is the goal of protein digestion in monogastric animals?
Break protein down to amino acids for absorption
What does HCl do? Where does it come from?
Denature protein and activate pepsinogen
Parietal cells
Where does pepsinogen come from?
Chief cells
What type of enzyme is pepsinogen?
Proteolytic
What type of peptidase is pepsinogen?
Endopeptidase
What does an Endopeptidase do?
Cleaves peptide bond in amino acid sequence
What are the pancreatic enzymes?
Trypsin
Chymotrypsin
Carboxypeptidase
Which pancreatic enzymes are Endopeptidases? Exopeptidase?
Trypsin and chymotrypsin
Carboxypeptidase
What are the duodenal enzymes?
Enterokinase amino peptidase
Dipeptidase
Look at protein digestion picture on page 74
Look at protein digestion picture on page 74
How many carrier systems are there?
At least 5
Why is a carrier system used?
To get amino acids across mucosal cell membrane
What are the 2 processes of protein synthesis?
Transcription and translation
What is transcription?
DNA is used to make mRNA which ends up in the cytoplasm
Where does translation occur?
On ribosomes in endoplasmic reticulum
What is mRNA a “recipe” for?
Protein amino acid sequence
What is mRNA divided into? What do they do?
Codons (3 base pairs)
Code for a specific amino acid
What does tRNA do?
Carry specific amino acids to ribosomes for protein synthesis
What does turnover refer to?
Constant protein turnover that is energy demanding
What is turnover a part of?
Maintenance energy requirement
When does protein synthesis stop?
When a specific amino acid is not available when the ribosome needs it
What is the limiting amino acid concept based on?
Deficiency of one essential amino acid
What are four things that are considered catabolism or are catablized?
Constant body turnover
Amino acids in excess of requirements
Non-limiting amino acids
Amino acids for energy production
What is deamination?
Removal of amino group as ammonia
What is the general reaction for deamination?
Amino acid –> Keto Acid + NH3
(enzyme over arrow/water under arrow)
What is transamination?
Transfer of amino group from one compound to another
What is the general reaction for transamination?
Amino acid 1 + Keto Acid 2 –> KA1 + AA2
(enzyme over arrow/ Vit. B6 under arrow)
What do ketogenic amino acids become?
Acetyl CoA
What are the 3 ketogenic amino acids?
Leucine, isoleucine, and phenylalanine
What are the gluconeogenic amino acids?
All other amino acids that aren’t ketogenic and phenylalanine
Look at page 78 and 79
Look at page 78 and 79
What amino acids come in to the krebs cycle with pyruvate? (5)
Alanine
Cysteine
Glycine
Serine
Threonine
What amino acids come into the krebs cycle with Acetyl CoA? (3)
Isoleucine
Leucine
Tryptophan
What amino acids come in to the krebs cycle with acetoacetate? (5)
Leucine
Lysine
Phenylalanine
Tyrosine
Tryptophan
What amino acids come in to the krebs cycle with glutamate (becomes α-ketoglutarate)? (4)
Arginine
Glutamine
Histidine
Proline
What amino acids come into the krebs cycle with Succinyl CoA? (3)
Isoleucine
Methionine
Valine
What amino acids come into the krebs cycle with fumarate? (2)
Phenylalanine
Tyrosine
What amino acids come into the krebs cycle with oxaloacetate? (2)
Aspartate
Asparagine
What are the 7 symptoms of ammonia toxicity?
Muscle tremors
Slurred speech
Blurred vision
Ataxia, inccordination
Tetany, violent spasms
Comotose state
Death- acute 30 minutes, or could take days
What are the 4 steps of the urea cycle?
- Ammonia detoxification
- Nitrogen for urea synthesis enters as NH3 from deamination
- Requires 4 high energy phosphate bonds per urea molecule
- Fate of urea in blood (blood urea nitrogen):
Urine, rumen (via saliva), and cecum
What places in the body recycle urea?
Rumen and cecum
Can birds produce urea?
No
What do birds use as excretory product?
Uric acid which requires glycine
What do ruminants do with urea?
Recylce it to rumen (horses to cecum)
What does bacteria do in ruminant protein digestion?
Secrete protease which is eventually broken down to NH3 and a carbon skeleton
What is microbial protein?
Protein synthesized by microbes
What does nonprotein nitorgen (urea) use to make amino acids?
NH3 and carbon skeleton
What does feeding nonprotein nitrogen help do?
Meet tissue amino acid requirements
What does an escape protein do or not do?
It does not undergo ruminal degradation
What does heating the protein source of escape proteins do?
Decrease solubility which decreases the ability to be broken down
Place the following in decreasing order of escape protein amounts: SBM, fishmeal, grass.
Grass < SBM < Fishmeal
What is the purpose of NH3 and a carbon skeleton?
NH3 is produced rapidly and a carbon skeleton is needed at the same time
When is nonprotein nitrogen beneficial?
When proper CHO’s are also fed
Why are urea and hay not a good match for a diet?
Urea is a protein source, hay is a carbon energy source. Urea will be absorbed by kidney and the animal will urinate on the ground because fiber (cellulose) is not digested quickly
What does microbial protein come from?
Nonprotein nitrogen and soluble protein in the diet
What are amino acids available to tissue from?
Escape and microbial protein
Look at page 86
Look at page 86
Why can ruminants survive with low protein?
Becuase of urea and recycling
Why do ruminants and humans not compete for food?
Because of nonprotein notrogen and met amino acid requirements
Where are microbial and escape proteins digested and absorbed at?
Small intestine
In adult ruminants, what can protein requirements be met with?
100% microbial protein
In young or lactating ruminants, what can protein requirements be met with?
75% microbial proteins
25% escape proteins
How can you decrease protein solubility?
Heat
Coat with fat so bacteria can’t get to it
Chemically treat with formaldehyde
What is the biological value of egg protein?
95
What is the biological value of milk protein?
90
What is the biological value of meat protein?
90
What is the biological value of SBM protein?
75
What is the biological value of meat and bone meal?
70
What is the biological value of cereal grain?
60
What is the biological value of microbial protein?
75-80
