Biology · Chemistry

Lipids, Fats, and Biochemistry

1,130 Questions

Lipids, fats, and biochemistry explore the structure and function of biological molecules. This includes fatty acids, cholesterol, trans-fats, and cellular membranes. Questions on this topic frequently appear in science sections of competitive government exams.

Types of fats and lipidsCholesterol and human bodyFatty acidsCellular membranes

Lipids, Fats, and Biochemistry Questions

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

Triglyceride metabolism to convert fats into carbohydrates is helped by glyoxylate cycle. The organelle responsible for this is found in

  1. Rice seeds

  2. Caster seeds

  3. Wheat seeds

  4. More than one option is correct
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The glyoxalate cycle converts the fats into carbohydrates. This takes place in the organelles which are known as peroxisomes.

the lipids that are present in the cell are used to make energy.
This is found in many plants. This cycle is essential for seed germination.
So, the correct option is 'More than one option is correct'

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

State whether the following statements are true or false.
Lacteals absorb digested fat in the form of chylomicrons.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A lacteal is a lymphatic capillary that absorbs dietary fats in the villi of the small intestine. Triglycerides are emulsified by bile and hydrolyzed by the enzyme lipase, resulting in a mixture of fatty acids and monoglycerides. These chylomicrons then pass into the lacteals, forming a milky substance known as chyle.

So, the correct option is 'True'.

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

Main difference between brown fat and white fat is that the cells of brown fat

  1. Are multicoloured

  2. Have more mitochondria

  3. Are polygonal in shape

  4. All the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Brown fat cells are specialized for thermogenesis and contain a high density of mitochondria, which give the tissue its characteristic brown color. White fat cells primarily store energy and have fewer mitochondria.

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

The most abundant lipid in the cell membrane is:-

  1. Cutin

  2. Phospholipid

  3. Glycolipid

  4. steroid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The most abundant lipid present in the cell membrane is phospholipids.
  • The cell membrane is called lipid bilayer as it is a double layer membrane made up of phospholipids. 
  • Phospholipids consist of a polar head group and non-polar fatty acid tails. 
  • The arrangement of these phospholipids in the cell membrane makes the cell membrane permeable.
  • The correct answer is OPTION B.
Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

A pound of butter contains more usable energy than a
pound of sugar for a human because

  1. Sugar contains much more water than butter

  2. A fat molecule has more carbon-hydrogen bonds than a

    sugar molecule

  3. The butter is an animal product, where as the sugar is a

    Plant Product

  4. There is much more waste in digestion and absorption

    of sugar than of butter
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A pound of butter contains more usable energy than a pound of sugar for a human because a fat molecule has more carbon-hydrogen bonds than a sugar molecule. Butter contains fat molecules and sugar contains carbohydrates. Fat molecule have low ratio of oxygen and hydrogen comparison to carbohydrates and they have more carbon-hydrogen bonds than carbohydrates.

Multiple choice biology food for health fats fats and their test different nutrients in food

The ultimate source of energy in human beings is

  1. Fats

  2. Carbohydrates

  3. Proteins

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fats are broken down into free fatty acids (FFA) and triglycerides which can produce ATP through chemical reactions.

Fatty acids either circulate in the blood or are stored as triglycerides in adipose tissue and muscle.
Fat is a very energy dense nutrient, one gram of it provides nine calories of energy. 
Despite the large quantity of available energy that fat has it provides this energy at a much slower rate than carbohydrate. This is because the chemical reactions required for its breakdown are much more complex and time consuming. 

Multiple choice biology food for health fats fats and their test different nutrients in food

Saturated fat is

  1. Solid at room temperature

  2. Has fatty acids with no double bonds between the carbon atoms

  3. Is of animal origin.

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Saturated fats are simply fat molecules that have no double bonds between carbon molecules because they are saturated with hydrogen molecules. These are typically solid at room temperature and are found in animals.

So the correct option is 'All of the above'.

Multiple choice biology food for health fats fats and their test different nutrients in food

Carotenoids are composed of units called as

  1. Fatty acids

  2. Amino acids

  3. Isoprene

  4. Pyran
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Carotenoids are organic pigments that are found in the chloroplasts and chromoplasts of plants and some other photosynthetic organisms, including some bacteria and some fungi. Carotenoids can be produced from fats and other basic organic metabolic building blocks by all these organisms. All carotenoids are tetraterpenoids, meaning that they are produced from 8 isoprene molecules and contain 40 carbon atoms.

Multiple choice biology food for health fats fats and their test different nutrients in food

Neutral fats are different from carbohydrates in which of the following manners? 

  1. Neutral fats have more oxygen atoms than carbon atoms are compared to carbohydrate

  2. Neutral fats have fewer oxygen atoms than carbon atoms as compared to carbohydrates

  3. Neutral fats do not have oxygen atoms but carbohydrates contain oxygen atoms but carbohydrates contain oxygen atom

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Neutral fats (triglycerides) have a significantly higher proportion of carbon and hydrogen compared to oxygen than carbohydrates do. Carbohydrates generally have a 2:1 ratio of hydrogen to oxygen, while fats are much more oxygen poor.

Multiple choice biology food for health fats fats and their test different nutrients in food

Fats in the body are formed when

  1. Glycogen is formed from glucose.

  2. Sugar level becomes stable in blood.

  3. Extra glycogen storage in liver and muscles is stopped.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Carbohydrates are the preferred fuel for cellular respiration. Excess carbohydrates are stored as glycogen in muscles and liver. Glycogen storage is for short duration only. Glycogen reserves meet energy demand between meals and during intense physical exercises. Long term storage of carbohydrates occurs as fats. After storing glycogen, still extra carbohydrates available are converted to fats for long term storage in the body.

Multiple choice biology food for health fats fats and their test different nutrients in food

The molecule used by most animals for long term energy storage is

  1. Starch

  2. Fat

  3. Protein

  4. Glycogen
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The fats contain more energy per gram than carbohydrates and as a result of this, the body tends to use fat to store energy over long periods of time and uses carbohydrates to store energy short-term.
Therefore, the correct answer is option B.

Multiple choice biology food for health fats fats and their test different nutrients in food

Fats and carbohydrates are together called as 

  1. Protective foods

  2. Harmful foods

  3. Body building foods

  4. Energy giving foods
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

We need energy for doing work. Energy is provided by carbohydrates and fats. Carbohydrates and fats on oxidation liberate energy. As compared to fats, carbohydrates get easily oxidized and converted into glucose and provide energy. One gram of carbohydrate yields about 17 kilo-joule of energy, whereas one gram of fat produces 37 kilo-joule of energy. This is the reason why carbohydrates and fats are called as energy food.

Multiple choice biology food for health fats fats and their test different nutrients in food

Cholesterol is synthesised in

  1. Brunner's gland

  2. Pancreas

  3. Liver

  4. Spleen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Slightly less than half of the cholesterol in the body derives from biosynthesis de novo. Biosynthesis in the liver accounts for approximately 10% and in the intestines approximately 15%, of the amount produced each day. The cholesterol biosynthesis pathway involves enzymes that are in the cytoplasm, microsomes (ER), and peroxisomes. Synthesis of cholesterol, like that of most biological lipids, begins from the two-carbon acetate group of acetyl-CoA. Cholesterol synthesis does not occurs in pancreas, spleen and Brunner's gland. 

So, the correct answer is 'Liver'

Multiple choice biology food for health fats fats and their test different nutrients in food

Oxidation of which of the following substances in the body yields more amount of calories?

  1. Glucose

  2. Glycogen

  3. Protein

  4. Lipids
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Oxidation refers to the direct breakdown of nutrients for energy. Fats or lipids have the highest energy content of 9 kcal/gm while proteins and carbohydrates have 4 kcal/gm.
Therefore, the correct answer is option D.

Multiple choice biology food for health fats fats and their test different nutrients in food

Which category of compound is most concentrated energy source?

  1. Lipid

  2. Carbohydrates

  3. Proteins

  4. Vitamins
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Lipids are a group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, phospholipids, and others. The main biological functions of lipids include storing energy, signaling, and acting as structural components of cell membranes.
Triglycerides, stored in adipose tissue, are a major form of energy storage both in animals and plants. The adipocyte, or fat cell, is designed for continuous synthesis and breakdown of triglycerides in animals, with breakdown controlled mainly by the activation of hormone-sensitive enzyme lipase. The complete oxidation of fatty acids provides high caloric content, about 9 kcal/g, compared with 4 kcal/g for the breakdown of carbohydrates and proteins. Migratory birds that must fly long distances without eating use stored energy of triglycerides to fuel their flights.