Term
| What are the 4 structures of proteins? |
|
Definition
1. Primary Structure
- Long chains of Amino Acids (AA) joined together by peptide bonds
2. Regular Structure
- AA sequences will arrange themselves intro structures (ex. spirals or sheets)
3. Polypeptide Folding
- Polypeptide chains fold back on themselves to form 3D structures
- Most use globular formation to minimize surface: volume ratio
4. Association of Protein Subunits
- single polypeptides will form loarger protein complexes |
|
|
Term
| What is Protein denaturation? |
|
Definition
| Normal configuration of protein is lost due to changes in acidity, temperature or high salt concentrations |
|
|
Term
| True or False: Ruminant animals can synthesize many AA |
|
Definition
True
They have microflora in the rumen. |
|
|
Term
| What are the 2 limiting AA in a protein source? |
|
Definition
Lysine and Methionine
Soybean meal is high in both of these AA; thus, it is considered to be a high protein quality |
|
|
Term
| What is the average protein content of soybean meal? |
|
Definition
44% or 48%
44% = still has seedcoats
48% = meal taken from just flaked cotyledons after oil is extracted; used in poultry feed |
|
|
Term
| What do raw soybeans contain? |
|
Definition
Trypsin inhibitors
Trypsin is an enzume that cleaves peptide bonds. If inhibited, the protein passes through less digested
SOLUTION: heat soybean meal. Can feed raw soybeans to cattle |
|
|
Term
|
Definition
Enzyme that breaks down CO2 and NH3
deactivate this enzyme by heating soybean meal |
|
|
Term
| In soybeans, why are isoflavones good? |
|
Definition
| Have structures like estrogens. Soybeans are now able to be labeled as heart healthy |
|
|
Term
Why plant corn before soybeans? |
|
Definition
| Corn is fertilized to such a high nitrogen level. Soybeans are able to utilize this nitrogen ("second feeders") |
|
|
Term
List the following about soybeans:
Oil and protein content
Row width
Planting temperature |
|
Definition
Oil: 20%
Protein: 40-45%
Row width: 18 cm (15" in lecture note)
Plant temp: 10C |
|
|
Term
| What kind of crop rotation is used in Ontario? |
|
Definition
|
|
Term
| Why is continuous soybeans a bad idea? |
|
Definition
| See a build up of diseases, pests and soybean cyst nematodes |
|
|
Term
| What is Bradyrhizobium japonicum? |
|
Definition
Type of innoculant used on soybeans
Bacteria enter into soybean roots via infection threads on root hairs. Rhizobia will multiply in the nodules that form
Nodules get energy from photosynthesis, plant gets N from bacteria |
|
|
Term
| When is essential to innoculate a soybean field? |
|
Definition
When there is no indigenous population of rhizobia
Any time soybeans are grown in a first-time field
See a 30-50% yield response (depends in N status of soil) |
|
|
Term
| What happens if nodulation is poor in soybeans? |
|
Definition
| results in a poor protein content |
|
|
Term
| True or False: soybean rhizobia never die |
|
Definition
False
Some conditions, like tobacco sands (too hot) or low pH soils (<5.5) cause rhizobia to die |
|
|
Term
| What is pre-inoculated seed? |
|
Definition
| Seeds are covered with innoculant before sale. Polymers protect the innoculant and usually contain a fungicide & insecticide |
|
|
Term
| Why is it important to have an early planting date? |
|
Definition
See a yield response
Decreases risk of frost damage
Delayed planting reduces yield |
|
|
Term
| What is the standard planting depth for soybeans? |
|
Definition
1.5"
Be careful with soil crusting, as it can damage the hypocotyl |
|
|
Term
List the characteristics of the following deficiencies:
N and S
P
Fe
Mn |
|
Definition
N&S = light green colour
P = purple/red colour
Fe chlorosis = high pH soil. Yellow leaves at top of plant
Mn = interveinal chlorosis. Roundup inhibits Mn metabol. |
|
|
Term
| Why can potash fertilizer not be added in-furrow? |
|
Definition
K inhibits germination (it's a salt)
P burns the radicle of dicots
Best to use a 2x2 banding of fertilizer |
|
|
Term
| Name some of the major pests and diseases of soybeans |
|
Definition
Pests: aphids and Japanese beetle
Diseases: White Mould and Phytopthora root rot |
|
|
