91 lines
5.1 KiB
Markdown
91 lines
5.1 KiB
Markdown
Proteins are large, complex, organic molecules made up of **amino acids**.
|
|
- Contain carbon, hydrogen, oxygen, and nitrogen
|
|
- Found in plants, animals, bacteria, and viruses
|
|
- Major functions of protein in the body:
|
|
- To build new cells and many parts of cells
|
|
- As a component in hardened structures like hair and nails
|
|
- As enzymes to speed chemical reactions
|
|
- As lubricants to ease movement
|
|
- In clotting compounds in blood
|
|
- To build antibodies that fight disease organisms
|
|
- As compounds that help maintain fluid and pH balance
|
|
- As transporters
|
|
- To make certain hormones
|
|
- As an energy source (as a last resort)
|
|
# Introduction
|
|
- By helping to maintain fluid balance, proteins prevent **edema** (accumulation of fluid in tissues
|
|
- Proteins also help maintain **acid-base balance**.
|
|
- Maintaining the proper pH of body fluids
|
|
- Acts as a buffer
|
|
|
|
# Amino acids
|
|
- Amino acids are nitrogen containing chemical units that comprise proteins
|
|
- There are 20 different amino acids found in the proteins of the human body
|
|
- Each amino acid has a carbon atom that anchors
|
|
- Hydrogen atom
|
|
- Amino or nitrogen containing group
|
|
- R group (side chain)
|
|
- carboxylic acid group
|
|
- nonessential amino acids are a group of amino acids that the body can make
|
|
- Essential amino acids are amino acids the body cannot make or cannot make enough of to meet its needs
|
|
- Conditionally essential amino acids are the amino acids the body cannot make or cannot make enough of to meet its needs
|
|
- There are 9 essential acids and 11 non-essential acids
|
|
|
|
| Essential | Nonessential |
|
|
| ---------------------------- | ------------- |
|
|
| Histidine | Alanine |
|
|
| Isoleucine | Aspartic acid |
|
|
| Leucine | Asparagine |
|
|
| Lysine | Glutanic acid |
|
|
| Methionine | Serine |
|
|
| Phenylanaline | Argine |
|
|
| Threonine | Cysteine |
|
|
| Tryptophan (extra important) | GLutamine |
|
|
| Valine | Glycine |
|
|
| | Proline |
|
|
| | Tyrosine |
|
|
TT HILL MVP
|
|
|
|
# Synthesis
|
|
A specific order of amino acids is needed to formulate a protein.
|
|
|
|
# DNA
|
|
- DNA (deoxyribonucleic acid) provides instructions for making proteins.
|
|
- **Genes** are a portion of DNA
|
|
- To make proteins, cells assemble amino acids into specific sequences according to information from DNA
|
|
- A **peptide bond** is a chemical attraction that connects two amino acids together
|
|
|
|
# DNA Process
|
|
1. Protein synthesis begins when a section of DNA unwinds, exposing a single portion (a gene). The gene contains coded info about the order of amino acids that comprise a specific protein
|
|
2. The gene undergoes **transcription**, that is, the sequence of amino acids copied is copied in a special manner, forming **messenger RNA** (mRNA) in the process.
|
|
3. mRNA transforms the information concerning the amino acid sequence form the nucleus to **ribosomes**, protein manufacturing sites in cytoplasm.
|
|
4. During the **translation** process, ribosomes "read" mRNA. The coded instructions indicate which amino acid to add to the polypeptide chain and its sequence.
|
|
5. Each specific **transfer RNA** (tRNA) molecule conveys a particular amino acid to the ribosome.
|
|
6. At the ribosome, the amino acid that has been delivered by the tRNA attaches to the peptide chain, lengthening it.
|
|
7. When the translation process is complete, the ribosome release the polypeptide, and the new protein generally undergoes further processing at other sites within the cytoplasm.
|
|
|
|
Summary:
|
|
- Transcription: DNA unwinds, gene gets copied forming mRNA, happens in the nucleus
|
|
- DNA -> mRNA
|
|
- Translation: mRNA give info to ribosomes and they "read" mRNA. trNA gets each amino acid and brings it to the ribosome to be attached to the peptide chain. Happens in **cytoplasm**.
|
|
- mRNA -> ribosomes, ribosomes read mRNA -> tRNA grabs the amino acid needed -> ribosomes create peptide chain
|
|
|
|
# Protein Structure
|
|
- The shape of protein is important because it influences the compound's function
|
|
- Sickle cell anemia is an inherited form of anemia.
|
|
- **Denaturation** alters a protein's natural shape and function by exposing it to conditions such as heat, acids, and physical agitation. This change is permanent.
|
|
|
|
# In Foods
|
|
- Animal foods generally provide higher amounts of protein than similar quantities of plant foods.
|
|
- Certain parts of plants provide more protein than other parts
|
|
- Seeds, tree nuts, legumes supply more
|
|
- Fruits or edible leaves, roots, flowers, and stems of vegetables provide less
|
|
- Legumes are parts of plants that produce pods with a single row of seeds.
|
|
- Peas
|
|
- Peanuts
|
|
- Lentils
|
|
- Soybeans
|
|
- High quality (complete) protein is a protein that contains all essential amino acids in amounts that support the deposition of protein in tissues and the growth of a young person.
|
|
- Meat, fish, poultry, eggs, **milk**
|
|
- Low quality (incomplete) protein is a protein that lacks or has inadequate amounts of one or more of the essential amino acids
|
|
- A limiting amino acid is the essential amino acid found in the lowest concentration of a particular protein source |