Chapter 6: Proteins

having all of the different types of amino acids available..

enables the cells to produce all types of proteins as needed

Lots of water leaving cells

equally damaging to too much water entering the cell because it can cause cells to SHRINK. too few proteins, causing swelling

having too few proteins in the blood..(what happens, observed in)

leads to water exiting the cells into the interstitial fluid causing edema (swelling) - observed in individuals who are consuming very low energy diets.

smooth muscles (located where, ensure what)

located around blood vessels, organs of the digestive system, respiratory system, and urinary system •they ensure constant contraction to move substances within the organs

In heathy individuals

proteins rarely used for energy. •proteins not used because they have numerous important functions.

Proteins synthesis in the cell not permanent..

•once a protein is produced, it may be degraded because it may not be needed or has lost its function. •once protein broken down, resulting amino acids because part of the amino acid pool in the cell and can be re-used.

DNA's role in proteins (protein synthesis is...sequence of gene dictates...all cells..)

•protein synthesis not random, it is complex and expressed through genes in the DNA •sequence of gene dictates the specific amino acids that should be chemically connected to make the final protein product. •all cells do not synthesize the same proteins, jut proteins needed for their specific functions.

Functions of proteins as protective molecules.

•proteins function in immune system. •immune system cells produce and release proteins in the circulation called antibodies. •antibodies defend us against harmful pathogens. When they encounter anything that does not belong in our body, the antibodies signal other immune cells to launch an attack to destroy the pathogens.

secondary structure

•the different amino acids in the chain interact causing the chain to undergo twists called alpha helices and folds called beta pleated sheets.

tertiary structure (what shape, once in this structure..)

•the folding of the polypeptide continues, forming a three dimensional shape. •once in this structure, the protein has a unique shape, which enables it to perform a specific function in the cell

Primary structure

•the initial sequence of the amino acid •this structure occurs when the amino acids are covalently linked together in a specific sequence

essential amino acids

•the ones that our body cannot synthesize on its own and therefore we must obtain in our diet.

Skeletal muscles

•used for any form of physical activity

examples of complete proteins

•meat and animal products such as egg whites and cow milk. •from a plant source, soybeans are the most complete source of proteins.

Overall recommended dietary allowance of protein (g/kg and range of total caloric intake, for who is it higher)

0.8 grams per 1 kg of body weight. •total quantity of proteins in the diet should be in the 10-35% range of the total caloric intake. •recommendation for children, adolescents, pregnant and lactating mothers higher. •athletes and active people too

how many different amino acids exist in our body

20 different amino acids that exist in our body

Functions of proteins

Chemical reactions, signaling, fluid balance, acid-base balance, protection, transport, growth and development, and movement.

gluconeogensis (what happens, when occurs)

amino acids converted to glucose •unhealthy process that occurs in malnutrition or during prolonged starvation.

nonessential amino acids

amino acids that can be synthesized in the body if not consumed in the diet •just as important as essential amino acids.

deamination

amino group removed in a chemical reaction so that amino acids can be used for energy

Too much water entering a cell...

can lead to cell expansion and eventually cause the cell to burst

alkalosis (condition associated with..leads to..)

condition associated with high concentrations of bases in the circulation •leads to deleterious effects as well

complete protein

a protein source that has all of the essential amino acid

two major proteins found in muscles are

actin and myosin •amino acids from circulation build these proteins

Protein structure after translation...

after translation, protein then dissociates from the ribosome and undergoes further modification to obtain the correct shape in order to be function

In diet, important to../

get all of the essential amino acids.

Nuts

great source of proteins, but because of high fat content, their intake should be in low quantities

Legumes

high fiber- can lower risk of CVDS and certain forms of cancer

incomplete protein

if lacking even ONE essential amino acid, protein is incomplete.

cardiac muscles (make up what, which does what)

make up the heart, it beats constantly to ensure adequate delivery of blood to the body

gene expression (process for, starts with, each gene contains...structure and size depends on...genes serve as..)

process for protein synthesis •starts with genetical material from parents •each gene contains set of instructions on how to build up a specific protein with the proper amino acid sequence •structure and size of protein depends on genes set of instructions. •genes serve as a template for protein's synthesis.

transamination

the chemical reaction that involves converting an essential amino acid into a nonessential one.

what determines the function of a protein?

the number and the types of amino acids found ina protein

amino acids (what are they, made of what

• building blocks of proteins •made up of a central carbon that is connected to four other groups: an amino group, a carboxyl group, a hydrogen atom, and an R group

Function of Proteins in Movement

• no matter what type of physical activity we engage in, we rely on our muscles •skeletal muscle, cardiac muscle, and smooth muscle contraction is achieved by proteins.

when we consume proteins in our diet they are...and then...once in...

they are broken down to amino acids in the digestive system and then transported into our cells. •Once int he cell they are constructed into proteins

acidosis (what is, what can it change)

too much acid in the blood. •can change someone's respiratory pattern and have significant effects on the digestive system as well

R group

what makes each amino acid different

Protein Digestion (mouth, esophagus, stomach, duodenum)

•Mouth- mastication and salvia fragment the large clusters into small aggregates •esophagus- more mucus secretion •stomach- chief cells release pepsinogen, activated by hydrochloric acid (parietal cells of stomach) . Pepsinogen changed to pepsin (breaks down dietary large proteins) •duodenum/pancreas-from pancreas, proteolytic enzymes (trypsinogen, chymotrypsinogen, and procarboxypeptidase)- activated by enterokinase- breaks protein fragments into dipeptides • Aminopeptidase finished the digestion, breaking dipeptides into amino acid

components in proteins (what elements)

•On top of being made of carbon, hydrogen, and oxygen, protein also contains nitrogen atoms. •having nitrogen enables the cells to produce other nitrogen containing compounds •some amino aids have sulfur atoms too.

Transcription (RNA does, then what)

•RNA exits the nucleus to the cell cytoplasm and binds to the ribosomes. •then copies the gene into mRNA

Function of Proteins to Maintain Fluid Balance (largest amount of water..water balanced must..important to have because..)

•Water makes up large amount of our body •largest amount of water found in our cells •also have around our cells and in the plasma •water balanced must be maintained at all time. •important to have a balanced amount of electrolytes and proteins because these concentrations affect cellular water movements.

Function of Proteins in Cell Growth, Maintenance and Repair.

•all cells constantly dividing as children grow •body cells maintained; old cells die and new cells generated. •rate of cell division depends on the activity of the cell. •MITOSIS- process of cell division- regulated by proteins •many proteins mediate cell repair during the healing process after injury

Absorption of Proteins (how absorbed, amino acids taken to where, later they are shuttled to where)

•amino acids absorbed through the cells of the small intestine into the blood •amino acids taken to the major storage places in the liver and muscles •Later they are shuttled to the body tissues as needed

Involuntary muscles

•are cardiac muscles and smooth muscles

Voluntary muscles (are what, allow us to what)

•are the skeletal muscles found around our extremities, in our skull and face, and at the base of our lungs •these muscles allow us to interact with our environment, communicate with our surroundings, and breathe.

Chemicals that can't travel in the blood easily...

•blood circulating in the vessels carries many chemicals to be delivered to specific organs •however due to the watery composition of the blood, not all of these chemicals can travel easily. •ex. cholesterol and lipid hormones- water insoluble. •need transport protein.

quaternary structure

•certain proteins can interact further than tertiary structures. •multiple tertiary structures associate with each other.

Meats

•considered complete proteins because they contain all the essential amino acids •but they are high in saturated fat and cholesterol

Proteins (what are, exist where)

•essential macromolecules that have a broad array of functions •exist in every cell of our body •major part of our muscle mass •most diverse macromolecules

Soy products

•excellent source of protein, containing all of the essential amino acids and having very low amounts of saturated food and cholesterol

Proteins In The Diet (exist in , found in)

•exist in many different food products. •found in all types of meat, dairy products, soy products, legumes, whole grains, and nuts

How are proteins produced?

•from our diet, amino acids delivered to our cells. •once inside our cells, amino acids used to make specific proteins.

Beans

•high quality proteins though they are deficient in the essential amino acid methionine.

Function of Proteins as Hormones in Signaling (hormones important...many hormones made...examples)

•hormones important in regulating body functions, communication, and homeostasis •many hormones are made from AMINO ACID and/ or PROTEINS •ex. insulin and glucagon, and thyroid hormone- metabolism

function of proteins in PH Maintenance (if acids and basis not regulated..proteins function as...do what)

•if acidic and basic molecules not regulated properly, can lead to major shifts in the body's pH balance •BUFFERS- resist acid-base changes. Some of the common buffers in our circulation are proteins •bind to acids and bases.

Function of Proteins as Enzymes in Chemical Reactions (in order for cells to survive...rate of chem reaction...in chemical reaction substrates must...substrates don't always... enzymes help...chem reactions could not occur...)

•in order for cells to survive, they must have chemical reactions to produce molecules they need in order to sustain their functionality. •rate of chemical reaction varies. •in chemical reaction, substrates must interact in specific ways to generate a particular product •substrates don't always have an affinity for one another and may not interact well •ENZYMES HELP- they speed up chemical reactions by increasing the affinity of substrates to one another, forcing them to interact well. •lots of chemical reactions could not occur without availability of enzymes.

Function of proteins in transport (why is transport important, how proteins function- transport, channels, motor)

•in order for normal and efficient cellular function and proper communication, proper transport of substances throughout the body is necessary. Ensured by delivery of needed chemicals to the proper destination •proteins function in transporting chemicals and nutrients in the circulation. •also function in transporting chemicals ACROSS membranes and can move molecules within a cell as well •also can enable CHARGED ions and ENERGY molecules to enter and exit the cell •transport proteins bind to hydrophobic substances and enable them to travel in the circulation •proteins can function as channels and transporters allow the entry of needed substances into the cell •inside cell, motor proteins can bind molecules and facilitate their transport within cells

translation

•mRNA contains specific sequences of nucleotides called codons •transfer RNA read the codon on the mRNA and transfer and place the correct amino acid into the sequence.