Proteins

Summary

Protein, a vital nutrient found in foods like eggs, dairy, and legumes, is broken down into amino acids in our bodies to create new proteins essential for various functions. Humans utilize 20 amino acids, with 9 being essential and obtained through diet. Animal and plant-based foods like tofu and lentils can meet protein needs, with varied sources recommended for a complete amino acid profile. Protein requirements differ by age, gender, and health status, with some individuals at higher risk for deficiency. While excessive protein intake is generally safe, optimal levels are still under research.

Takeaways

• 🥚 Protein is a crucial component of the human diet, found in various foods such as eggs, dairy, seafood, legumes, meats, nuts, and seeds.
• 🔄 The body breaks down consumed protein into amino acids and reassembles them into new proteins for various functions, including fighting infections and aiding cell division.
• 🧬 Proteins are made up of chains of amino acids linked by peptide bonds, which fold into specific shapes to perform their roles.
• 🌀 Amino acids consist of a central carbon atom bonded to various groups, including an amino group, a carboxylic acid group, a hydrogen atom, and a unique side chain.
• 📘 Humans utilize about 20 different amino acids to create all types of proteins, with some being non-essential, conditionally essential, and essential amino acids.
• 🍽 Dietary protein is necessary to provide essential amino acids for the body's protein synthesis, including hormones and other molecules.
• 🔪 The digestion process, starting with proteolysis in the stomach, breaks down dietary protein into amino acids that are absorbed into the bloodstream and used by the body.
• 🥛 Animal-based foods like eggs, dairy, seafood, and meat, as well as soy foods, provide all nine essential amino acids in adequate amounts.
• 🌱 Plant-based foods vary in their amino acid content, but a varied diet can provide all essential amino acids, such as combining rice and beans or hummus with pita bread.
• 📊 Daily protein requirements are estimated by health organizations, with specific recommendations based on age, gender, and life stage.
• 🏋️‍♂️ Certain groups, like athletes, pregnant women, and older adults, may have increased protein needs, while malnourished individuals or those with certain health conditions may be at risk for protein deficiency.

Q & A

What is the primary role of protein in the human diet?

Protein is an essential part of the human diet, playing a crucial role in the body by fighting infections, helping cells divide, and being a major component of various bodily structures.

What happens to the protein we consume?

The protein we eat gets broken down and reformed into new proteins in our bodies through a process called proteolysis.

How is a protein structurally described?

Proteins are described as chains of amino acids bound to one another by peptide bonds, similar to a string of beads that get twisted and folded into a final protein shape.

What is an amino acid and what are its basic components?

An amino acid is a compound with a central carbon atom bonded to an amino group, a carboxylic acid group, a hydrogen atom, and a unique sidechain. The exception is proline, which has a small ring structure.

How many amino acids does the human body use to make proteins?

Humans use about 20 amino acids to make proteins, which include alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine.

What are non-essential amino acids and how do they differ from essential amino acids?

Non-essential amino acids are those that the body can synthesize on its own, such as alanine, asparagine, aspartic acid, glutamic acid, and serine. In contrast, essential amino acids cannot be synthesized by the body and must be obtained through diet.

What are conditionally essential amino acids and under what circumstances might they become essential?

Conditionally essential amino acids are those that healthy bodies can make under normal circumstances, like arginine, cysteine, glutamine, glycine, proline, and tyrosine. However, they may become essential in cases of starvation or certain inborn errors of metabolism.

What is proteolysis and how does it relate to protein digestion?

Proteolysis is the process of breaking down proteins into smaller units or individual amino acids. It begins when food reaches the stomach, with hydrochloric acid denaturing the protein and pepsin breaking it into smaller chains, which are further digested in the duodenum by pancreatic enzymes.

Why are animal-based protein foods considered important in a diet?

Animal-based protein foods like eggs, dairy, seafood, and meat are important because they provide all nine essential amino acids in adequate amounts, which are necessary for the body to synthesize its own proteins and other molecules.

How can plant-based foods meet protein needs and what are some examples of protein-rich plant foods?

Plant-based foods like soy, whole grains, legumes, nuts, and seeds can provide all essential amino acids, though some may require a combination of different foods to cover all needs. Examples include tofu, lentils, rice and beans, hummus and pita bread, and oatmeal with almond butter.

What are the general daily protein requirements for healthy adults according to the World Health Organization and the U.S. Recommended Dietary Allowance?

The general daily protein requirements for healthy adults are about 0.8 grams per kilogram of body weight, as estimated by both the World Health Organization and the U.S. Recommended Dietary Allowance.

How do protein needs vary by age and gender, and what are the specific recommendations?

Protein needs vary by age and gender. Children aged 1 to 3 are recommended to get 13 grams, ages 4 to 8 need 19 grams, and ages 9 to 13 need 34 grams. Females aged 14 and above need 46 grams per day, males aged 14 to 18 need about 52 grams, and males 19 and older need 56 grams per day.

What are some health conditions that may increase protein needs?

Certain health conditions such as malnutrition, trauma, burn injuries, and conditions impacting nutrient absorption like inflammatory bowel disease may increase protein needs compared to the general population.

Is there a health risk associated with eating a lot of protein, and what are the exceptions?

Except for certain circumstances like kidney disease, there usually isn't a health risk associated with eating a lot of protein because our bodies are able to process it.

Outlines

00:00

🥚 Protein's Role and Amino Acids

This paragraph delves into the significance of protein in the human diet, highlighting its presence in various foods and its crucial role in the body. Proteins are broken down into amino acids, which are the building blocks for new proteins that perform a myriad of functions, from fighting infections to aiding cell division. The paragraph explains the structure of amino acids, identifying the 20 types used by the human body, and categorizes them into essential, conditionally essential, and non-essential based on whether they can be synthesized by the body or must be obtained through diet. It also discusses the process of proteolysis, which is how dietary protein is broken down and absorbed in the body, and notes that both animal-based and plant-based foods can provide a complete amino acid profile, emphasizing the importance of dietary variety.

05:01

📊 Daily Protein Requirements and Sources

The second paragraph focuses on the recommended daily protein intake according to the World Health Organization and the U.S. dietary allowances, providing specific guidelines for different age groups and genders. It also addresses the increased protein needs of certain populations, such as pregnant and breastfeeding women, athletes, and older adults. The paragraph clarifies that while there is ongoing research on the optimal protein intake, there are no significant health risks associated with high protein consumption for most individuals, except in cases of kidney disease. It concludes by emphasizing that protein deficiency is a concern for specific health conditions and that a varied diet, whether omnivorous, vegetarian, or vegan, can meet protein requirements, with examples provided for achieving the recommended daily protein intake.

Keywords

💡Protein

Protein is a macronutrient that is crucial for the human diet and is the main focus of the video. It is composed of amino acids and is vital for functions such as fighting infections and aiding cell division. In the script, protein is described as being found in various foods and is essential for the body to create new proteins.

💡Amino Acids

Amino acids are the building blocks of proteins, with each one having a unique side chain. The script explains that there are about 20 amino acids used by the human body to create various proteins. They are the core components that, when strung together, form the structure of proteins.

💡Peptide Bonds

Peptide bonds are the chemical links that connect amino acids together to form proteins. The script describes how these bonds are like strings of beads, which are twisted and folded to create the final shape of a protein.

💡Essential Amino Acids

Essential amino acids are those that the human body cannot synthesize and must be obtained through diet. The script lists nine essential amino acids and emphasizes their importance in the diet to ensure the body can produce the necessary proteins.

💡Non-essential Amino Acids

Non-essential amino acids are those that the body can produce on its own. The script mentions five such amino acids, which are not required to be consumed through diet because the body can generate them.

💡Conditionally Essential Amino Acids

Conditionally essential amino acids are those that the body can synthesize under normal conditions but may require dietary intake under certain circumstances like starvation or specific health conditions. The script identifies six amino acids as conditionally essential.

💡Proteolysis

Proteolysis is the process of breaking down dietary proteins into their constituent amino acids. The script describes this process starting in the stomach with hydrochloric acid and pepsin and continuing in the small intestine with pancreatic enzymes.

💡Dietary Protein

Dietary protein refers to the protein obtained from food sources. The script discusses how dietary protein is necessary to provide the essential amino acids needed for the body's protein synthesis and other vital functions.

💡Plant-Based Protein

Plant-based protein comes from plant sources like legumes, nuts, and seeds. The script highlights that plant-based foods can also provide a complete amino acid profile, with examples given such as tofu and lentils.

💡Animal-Based Protein

Animal-based protein comes from sources like eggs, dairy, seafood, and meat. The script points out that these foods typically provide all nine essential amino acids in adequate amounts.

💡Protein Requirements

Protein requirements refer to the amount of protein needed daily to maintain health. The script provides specific recommendations based on age, gender, and life stage, and also mentions that certain groups like athletes may have higher needs.

Highlights

Protein is an essential part of the human diet found in various foods like eggs, dairy, seafood, legumes, meats, nuts, and seeds.

Proteins in our bodies are broken down and reformed into new proteins, playing roles from fighting infections to helping cells divide.

Proteins are chains of amino acids bound by peptide bonds, similar to a string of beads.

When we eat protein, it gets broken down into individual amino acids.

Amino acids have a central carbon atom bonded to an amino group, a carboxylic acid group, a hydrogen atom, and a unique sidechain.

Proline is unique among amino acids with a tiny ring structure instead of a sidechain.

Humans use about 20 amino acids to make all types of proteins.

There are five non-essential amino acids that our bodies can make: alanine, asparagine, aspartic acid, glutamic acid, and serine.

Six conditionally essential amino acids can be made by healthy bodies under normal circumstances: arginine, cysteine, glutamine, glycine, proline, and tyrosine.

Nine essential amino acids must be obtained from food: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Dietary protein provides essential amino acids needed to make our own proteins, hormones, and other important molecules.

Proteolysis is the process of breaking down dietary protein into amino acids, starting in the stomach with hydrochloric acid and pepsin.

Further digestion in the duodenum involves pancreatic enzymes that break down oligopeptides into tripeptides, dipeptides, and individual amino acids.

Animal-based protein foods like eggs, dairy, seafood, and meat provide all nine essential amino acids in adequate amounts.

Soy foods are unique plant-based foods that also provide all nine essential amino acids in adequate amounts.

Most other plant foods have varying amounts of amino acids, but a variety of plant-based foods can provide all nine essentials.

Daily protein requirements for healthy adults are about 0.8 grams per kilogram of body weight.

Protein needs vary by age, gender, and health status, with specific recommendations for children, adolescents, and older adults.

Pregnant and breastfeeding women, athletes, and older adults may have elevated protein needs.

Eating a lot of protein is generally safe, except in cases of kidney disease.

Everyone, whether omnivorous, vegetarian, or vegan, can get enough protein by eating a variety of foods.

Transcripts

Protein is an essential part of the human diet. It's found in a variety of foods like eggs

dairy seafood legumes meats nuts and seeds

Regardless of the source the protein that we eat gets broken down and reformed into new proteins in our bodies

These proteins do everything from fighting infections to helping cells divide. You name it

They're doing it at its simplest a protein is a chain of amino acids bound to one another by peptide

Bonds like a string of beads

These strings get twisted and folded into a final protein shape

When we eat protein, it gets broken down into its individual amino acids

Most amino acids have a central carbon atom bonded to one amino or nitrogen-containing group and one

Carboxylic acid group. That's why it's called an amino acid

The carbon also has one hydrogen atom and a sidechain which is unique to each amino acid

The exception to this is prolene, which is a tiny little ring structure instead

Although there are hundreds of amino acids in nature humans only use about 20 of them to make basically every type of protein

they include

alanine arginine asparagine aspartic acid cysteine glutamic acid glutamine glycine

histidine isoleucine leucine lysine

methionine phenylalanine

prolene serine threonine

tryptophan tyrosine and valine

Huh? That's twenty

One way to divide them is by defining which ones our bodies can make and which ones we can't

There are five amino acids alanine asparagine aspartic acid glutamic acid and serine that we can get from foods

But we can also make ourselves

These are called non-essential amino acids

Then there are six that we call conditionally essential because healthy bodies can make them under normal circumstances arginine cysteine

glutamine glycine proline and tyrosine

But we can't make them in cases like starvation or certain inborn errors of metabolism

Finally there are nine of them that we can only get from food

histidine isoleucine

leucine lysine methionine phenylalanine threonine

Tryptophan and valine we call these the essential amino acids

Dietary protein provides the essential amino acids that are needed to make our own proteins

hormones and other important molecules a circle of life of sorts but to do so

We need to break the dietary protein down first through a process called proteolysis

when we first eat a protein containing food proteolysis begins when the food reaches the stomach

First hydrochloric acid denatures the protein unfolding it and making the amino acid chain more accessible to enzymatic action

Then pepsin which is a itself made by gastric chief cells enters the picture

pepsin cludes any available protein into smaller oligopeptide chains

Which move into the duodenum where a second set of digestive enzymes made by the pancreas

further chopped the oligopeptides into tripeptides

dipeptides and

individual amino acids

These can all be taken up to the intestinal cells where died and tripeptides are then converted into amino acids

Some amino acids remain in these cells and are used to synthesize

intestinal enzymes and new cells

But most enter the bloodstream and are transported to other parts of the body in general

animal-based protein foods like eggs

Dairy seafood and meat provide all nine essential amino acids in adequate amounts

Soy foods are unique in that they are plant-based and also provide all nine essential amino acids in adequate amounts

most other plant foods including whole grains legumes nuts and seeds

Have high amounts of some amino acids and low amounts of others

Hearing this it might be easy to assume that animal-based foods provide more protein than plant-based ones

But as it turns out a cup of tofu has the same number of grams of protein as three ounces of steak chicken or fish

and

half a cup of lentils has more grams of protein than an egg and

Not all plant foods are low in the same amino acids

so eating a variety of plant-based foods can provide all nine of the essentials for

Example pairing protein sources like rice and beans or hummus and pita bread or oatmeal topped with almond butter

However, in terms of volume it may be necessary to eat more plant-based foods to get a similar amount of protein and amino acid

profile provided by animal-based proteins

generally speaking daily protein requirements are based on studies that estimate the minimum amount of protein needed to avoid a

progressive nitrogen loss

the World Health Organization guidelines and the u.s

Recommended dietary allowance each estimate that daily protein requirements for healthy adults are about point

eight grams per kilogram of body weight

Protein recommendations per day vary by age as well children one to three years of age are recommended to get 13 grams

for ages 4 to 8 19 grams are recommended and

Between ages 9 and 13 34 grams are recommended whether a person is male or female also impacts protein needs

Females ages 14 and above are recommended to get 46 grams of protein per day

males aged 14 to 18 needs slightly more about 52 grams per day and

Males 19 and older are recommended to get 56 grams per day

some groups like pregnant and breastfeeding women as well as athletes have elevated needs and

Older adults may also benefit from eating more protein

Getting the right amount of protein per day can be achieved in multiple ways

for example

one serving of Greek yogurt with breakfast a salad topped with three ounces of chicken for lunch and

Three to four ounces of fish at dinner provides about 64 grams of protein

getting the same amount of protein could also be achieved by eating a cup of tofu scramble and a slice of peanut butter toast for

Breakfast a cup of shelled edamame with lunch and one cup of lentils and brown rice at dinner

Which also offers about 64 grams of protein in total?

Now the fact is that it's still unclear. What an optimal amount of protein is and the research is ongoing in

Clinical settings. There are certain individuals who may be at risk for a protein deficiency

including patients with malnutrition

Trauma and burn injuries as well as various conditions impacting nutrient absorption like inflammatory bowel disease

These individuals may have increased protein needs compared to the general population

Except for certain circumstances like kidney disease there usually isn't a health risk associated with eating a lot of protein

Because our bodies are able to process it

Alright is a quick recap

Protein is a cornerstone of the human diet and a major component of our bodies

There are five non-essential six conditionally essential and nine essential amino acids

We need to get essential amine acids from our diet

Protein needs vary depending on lifecycle stage level of physical activity and health status

Some health conditions may put people at risk for protein deficiency or increased protein needs

Everyone whether omnivorous vegetarian or vegan can get enough protein by eating a variety of foods