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 biology economic importance of plants and animals uses of angiosperms importance and classification of angiosperms classification of angiosperms importance of plants

Assertion : Vegetable oils are fats, which are present in plant cells in soluble form.

Reason : Vegetable oils only occur in cells of the embryo.


  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion

  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion

  3. If the assertion is true but the reason is false

  4. If both the assertion and reason are false

  5. If the assertion is false but reason is true
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Vegetable oils and fats are present in the form of small insoluble droplets within the plant cells. They occur in the seeds and most commonly in the endosperm and cotyledons. In most of the cereals, the fat occurs in the embryo. 

Olive and palm oils are two important examples that are obtained from the fleshy pericarp of the fruit. Oils and fats are extracted from the roots, stems and foliage very less frequently.
So the correct option is D.

Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Epinephrine and eicosanoids finds their receptors on

  1. Cell wall

  2. Plasma membrane

  3. Inner matrix

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  •  Eicosanoids are compounds that include prostaglandins, prostacyclins, leukotrienes, and thromboxanes.
  • Lipid insoluble hormones such as eicosanoids bind to receptors on the outer surface of the plasma membrane, via plasma membrane hormone receptors.
  • The amino acid-derived hormones epinephrine and norepinephrine bind to beta-adrenergic receptors on the plasma membrane of cells.
  • Hence the Epinephrine and eicosanoids find their receptors on the plasma membrane.
  • So, the correct answer is 'Plasma membrane'.
Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Which of the following is responsible for steroid production?

  1. Salt

  2. Lipids

  3. Cholesterol

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

  • Cholesterol also plays a role in synthesizing the steroid hormones aldosterone, which is used for osmoregulation, and cortisol, which plays a role in metabolism. 
  • Cholesterol is also the precursor to bile salts, which help in the emulsification of fats and their absorption by cells. Hence,  Lipids is responsible for steroid production.
So, the correct answer is 'Lipids'.

Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Which of the following is not involved as $2^{nd}$ messenger?

  1. cAMP

  2. DAG

  3. Phospholipase
  4. $IP _{3}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

cAMP, DAG, and IP3 are well-known second messengers. Phospholipase C is an enzyme that generates second messengers (like DAG and IP3), but it is not a second messenger itself.

Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Receptors are :

  1. Proteins

  2. Lipids

  3. Carbohydrates

  4. Nucleic acids
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Receptor is a molecule usually found on the surface of a cell, that receives chemical signals from outside the cell. When such external substances bind to a receptor, they direct the cell to do something, such as divide, die, or allow specific substances to enter or exit the cell.

Receptors are proteins embedded in either the cell's plasma membrane (cell surface receptors), in the cytoplasm, or in the cell's nucleus (nuclear receptors), to which specific signaling molecules may attach.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Complex fatty acids that function as intercellular messengers are

  1. Prostaglandins

  2. Catecholamines

  3. Sphingolipids

  4. Steroids
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • The prostaglandins are a group of physiologically active lipid compounds called eicosanoids having diverse hormone-like effects in animals.
  • Prostaglandins have been found in almost every tissue in humans and other animals. 
  • They are derived enzymatically from the fatty acid arachidonic acid. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring. 
  • They are a subclass of eicosanoids and of the prostanoid class of fatty acid derivatives. Hence, Prostaglandins are complex fatty acids that function as intercellular messengers.
So, the correct answer is 'prostaglandin'.

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Fats and carbohydrates can be differentiated based on the fact that ___________. 

  1. Carbohydrates are always steroids.
  2. Carbohydrates have a $H : O$ ratio of $2 : 1$.

  3. Fats are known as starch.
  4. Fats have a $H : O$ ratio with much more oxygen than hydrogen.

  5. Fats always contain nitrogen.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carbohydrates are made up of C: H: O, having H and O in the ratio of 2:1 and the general formula is (CH2O)n. Sources of carbohydrates in our food are cereals and pulses. The caloric value is 4.1 kcal/g.

Fats and all fat-like substances are called lipids. Sources are Butter, ghee, liver oil, vegetable cooking oil. They have high Caloric value as compared to carbohydrates which is 9.45 kcal/g.

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

${C} _{n}{H} _{2n}{O} _{n}$ is the formula of

  1. Fatty acid

  2. Fat

  3. Glycerol

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

CnH2nOn is a general formula of monosaccharides. Monosaccharides are the simplest carbohydrates which cannot be hydrolyzed into smaller units. They usually have 3-7 carbon atoms per molecule. They are the compounds of carbon, hydrogen, and oxygen in which hydrogen and oxygen occur in the ratio of 2:1 as in a molecule of water. Thus, they are also known as hydrates of carbon. 

A fatty acid is an unbranched chain of carbon atoms with each carbon atom forming four bonds to other atoms It has a carboxylic group at one end and and the hydrogen atom bonded to all or most carbon atoms. 
Fats are formed as a result of esterification of fatty acids with various alcohols and glycerol is one of the alcohols which forms the true fats. Its formula is C$ _3$H$ _8$O$ _3$.
Thus, the correct answer is option D. 

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Inulin is a

  1. Lipid

  2. Carbohydrate

  3. Protein

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

Inulin is a storage polysaccharide in roots of Dahlia and related plants. It is also known as a fructan. It is not metabolized in the human body and is readily filtered through the kidney. Therefore, it is used in testing kidney function. Thus, the correct answer is B.

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Which is odd - 

  1. chitin carbohydrates

  2. Pectin proteins

  3. Steriod lipid

  4. Wax lipid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Chitin carbohydrates are the oldest in the given as it is a carbon-based factor. protein, lipids consist chain of nitrogen, hydrogen and carbon atoms however carbohydrate consists of a longer chain of carbon as well as various other groups of compounds. so, the correct option is 'chitin carbohydrates'.

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Decreasing order of amount of organic compound in animal body __________________.

  1. Carbohydrate, Protein, Fat and Nucleic acid

  2. Protein, Fats , Nucleic acid and Carbohydrate and nucleic acid

  3. Protein, Fats, Carbohydrate and Nucleic acid

  4. Carbohydrate, Fats, Proteins and Nucleic acid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The protein is the most important component of a cell. It forms an integral part of the cell membrane of all plants and animal cells. As a result protein is found in maximum amount in  human body.
Most of the hormones which are produced in the body and also constituents are blood are made up of proteins.
Apart from protein fat also has a considerable amount of mass in the body. this is followed by carbohydrate and the nucleic acid which is in least amount in the body.
Thus the correct option is C.



Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Chemical nature of chitin is 

  1. Carbohydrate

  2. Protein

  3. Fat

  4. Nucleic acid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Chitin is a carbohydrate. It is a long-chain polymer of a N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world. It is a characteristic component of the cell walls of fungi, the exoskeletons of arthropods such as crustaceans (e.g., crabs, lobsters and shrimps) and insects, the radulae of molluscs and the beaks and internal shells of cephalopods, including squid and octopuses. The structure of chitin is comparable to the polysaccharide cellulose, forming crystalline nanofibrils or whiskers. 

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Which of the following do not provide energy for animals?

  1. Fats

  2. Carbohydrates

  3. Vitamins

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

In animals fats, carbohydrates and proteins are responsible for generation of energy.
Proteins are metabolized by breaking down into individual amino acids by various enzymes and hydrochloric acid present in the gastro-intestinal tract which are further broken down to α-keto acids which can be recycled in the body for generation of energy, and production of glucose or fat or other amino acids.
Fats are the major contributor of the molicules like acetyl-CoA which is an integral part of Krebs cycle and generates energy.
Carbohydrates takes part in cellular process like glycolysis and leads to generation of energy.
Vitamins are not directly involved in generation of energy although they indirectly support the process of energy production.
So, the correct answer is option C.

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

${C} _{n}{H} _{2n}{O} _{n}$ is the formula of

  1. Carbohydrate

  2. Fatty acid

  3. Fat

  4. Nucleic acid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A monosaccharide is the simplest form of carbohydrate which is composed of carbon, hydrogen, and oxygen. The basic formula of the monosaccharide is C$ _n$H$ _{2n}$O$ _n$. For example, the formula for the most common monosaccharide, glucose is  C$ _6$H$ _{12}$O$ _6$. So, the correct answer is option A.