Molecules of Life

Question 1

What is a macromolecule?

Answer 1

It is a big molecule made from smaller units named monomer.

Question 2

What is monomer?

Answer 2

It is the smallest unit also called building blocks and where many monomers form polymers.

Question 3

What is a starch?

Answer 3

It is a polymer made from glucose monomer. Starch is glucose molecules covalently bounded.

Question 4

What is the function of carbohydrate and what is the chemical reaction?

Answer 4

To fuel and structure your body. eg: glucose
The C and H bonds store energy and by the cellular respiration, the chemical bonds in glucose are broken down to create energy.

Question 5

Of what carbohydrate is made of?

Answer 5

C, H & O. It is a polymer made of sugar units.

Question 6

What is the different between monosaccharide, disaccharide and polysaccharide?

Answer 6

Monosaccharide: eg: fructose and glucose (building blocks). It is 1 sugar molecule that has the same chemical formula but different shapes and properties.
Disaccharide: eg: sucrose and lactose. There are 2 sugars bonded.
Polysaccharide: This is a complex carbohydrate (starch).

Question 7

What is the difference between short-term and long-term energy?

Answer 7

Short-term: high rush that drops fast

Long-term: Slow rush and keep same energy for long

Question 8

What happens to the excess of glucose?

Answer 8

It is also called “blood sugar” and is a fuel for cellular activity. For temporary storage, it will be transforms into glycogen and for long-term storage, it will be transformed as fat.

Question 9

What is glycogen?

Answer 9

Glycogen is a complex carbohydrate molecule with glucose.

Question 10

Which molecule is not digestible for humans?

Answer 10

Carbohydrates because it is usually a structural material for invertebrate animals and plants called chitin. It is basically a shell or tree bark. Cellulose which is really close to starch is also not digestible.

Question 11

What is cellulose?

Answer 11

It is the major component for plant cell wall that provides structural support. It’s the major component of wood, a source of pulp and paper. It is also the major component in cotton.

Question 12

What is the difference and resemblance between starch and cellulose?

Answer 12

Both made of glucose monomer. However, starch is digested by mammals, whereas cellulose is not.

Question 13

What are lipids?

Answer 13

Mostly made with C & H bonded by non-polar covalent bonds and is hydrophobic. There are 3 main types of lipids: fats & oil, sterols and phospholipids. Fat and oil have a long term energy storage & insulation. Sterols regulates growth and development and phospholipids form cellular membranes.

Question 14

Describe oil and fats.

Answer 14

Fats = solid in room temperate
Oil = liquid in room temperature
It is a long-term energy storage and insulation
In its structure, the head is hydrophilic and made of glycerol and the tail is hydrophobic made of 3 fatty acids chains.

Question 15

What is a fatty acid?

Answer 15

It is saturated fats with no double bounds. or unsaturated fats with 1 or more double bounds.

Question 16

Why are saturated fats dangerous for you?

Answer 16

Because it increases the bad LDL cholesterol and increases the risks of coronary heart disease. You are also more likely to store it as fat.

Question 17

How can you identify saturated fats?

Answer 17

It has no double bonds, it solidifies at room temperature and it is often animal fats.

Question 18

What is the difference between LDL and HDL cholesterol?

Answer 18

LDL increases plaque build up in the blood vessel which make it bad and HDL decreases and clean up the plaque.

Question 19

Why is plaque dangerous?

Answer 19

It can cut off oxygen supply and cause damage or death to the heart tissue.

Question 20

How do you recognize unsaturated fat?

Answer 20

It bends in fat acids and has a double bond that replaces hydrogen in fatty acid. It is often vegetable oil or fish oil.

Question 21

What are the advantages of unsaturated fat?

Answer 21

It increases HDL cholesterol, therefore reduces risks of heart diseases and is less likely to store as fat.

Question 22

What are trans fat?

Answer 22

They are an artificial addition of hydrogen atoms called hydrogenation to make fat more saturated giving more flavor, texture and sheif-life. It can be found in hydrogenated vegetable oil.

Question 23

Why are trans fat dangerous?

Answer 23

It is the worst form of fat because it increases LDL cholesterol and decreases HDL, therefore increases the chances to get heart diseases.

Question 24

What are the 7 functions of proteins in the living organism?

Answer 24

• Structure (hair, fingernails, tendons, etc.)
• Protection (help system fight, coagulate)
• Regulation (control cell activity)
• Contraction
• Transportation of molecules
• Storage
• Facilitate chemical reactions (enzymes)

Question 25

What are amino acids?

Answer 25

They are the monomer units of proteins

Question 26

How many different amino acids exists?

Answer 26

There are 20 different amino acids and they differ from each other in side chain composition.

Question 27

Why are amino acids essential?

Answer 27

Because they help for growth, repair and replacement.

Question 28

How can you get all 20 amino acids?

Answer 28

The human body doesn't produce all 20 amino acids, therefore it needs to be part of our diet.

Question 29

What is the difference between complete and incomplete proteins?

Answer 29

Complete proteins have all essential amino acids and is usually found in animal products. Incomplete proteins are usually from plant sources but can be combined to procure all 20 called complementary proteins.

Question 30

Describe the primary structure of proteins.

Answer 30

The sequence of amino acids in polypeptide are similar to letters spelling a word. Therefore, if there is one mistake in a letter, the chain will not work. It in joined by a covalent bond called peptide bond. Its property is determined by primary sequence.

Question 31

Describe the secondary structure of proteins.

Answer 31

It is created by hydrogen bonds between the amino acids in polypeptide chain. There are 2 basic patterns: the aplha-helix in coil shape and the beta-sheet in zig-zag folding.

Question 32

Describe the tertiary structure of proteins.

Answer 32

It is made by hydrogen bonds and covalent sulfur-sulfur bonds. The folding and bonding of the secondary and tertiary structures will create a 3D structure.

Question 33

Describe the quaternary structure.

Answer 33

It is usually 2 or more polypeptide chains bonded together and function as one functional unit. Each polypeptide is called subunit.

Question 34

What does denaturation do to the protein structure?

Answer 34

In extreme environment conditions like temperature or pH, the protein structure unfolds and is irreversibly disrupted from its shape and function.

Question 35

Describe protein digestion.

Answer 35

It is the process of protein denaturation where the digestive enzymes break up proteins into amino acids. Amino acids are then used as raw material to make new proteins or used as an energy source.

Question 36

What are enzymes?

Answer 36

Enzymes are an important class of proteins that facilitate chemical reactions. There are two types: material that enzymes work on and binds to active site and products that are the material after the chemical reaction.

Question 37

What is activation energy?

Answer 37

It is a chemical reactions in the organism that either release or consume energy. Reactions sometimes need a push to initiate the reaction which is the activation energy. Enzymes act as a catalyst by lowering the activation energy.

Question 38

What are the chemical and physical factors that influence enzyme activity?

Answer 38

1. enzyme ? sustrate concentration 2. Temperature 3. pH 4. Presence of inhibitors or activators

Question 39

What is the enzyme activity?

Answer 39

It is the rate which enzyme catalyzes reaction influence by the chemical and physical factors. The rate of reaction increases with the addition of enzymes or substrate causing the increased rate of collision between enzyme and substrate molecules.

Question 40

How does temperature affect the activation energy?

Answer 40

The reaction rates increases the temperature to the optimal temperature for enzyme. It will often lose its shape or denature after the reaction rate decrease.

Question 41

What is the role of nucleic acids?

Answer 41

It encodes information on how to build and run the body and carry the genetic information. It also play a central role in directing protein production.

Question 42

What are nucleotides and what is the structure?

Answer 42

They are the building blocks of nucleic acids. There are 3 parts: the phosphate group, sugar, nitrogen and containing base.

Question 43

How is DNA formed?

Answer 43

The phosphate group and sugar of nucleotides are joined by covalent bonds. Nitrogen containing bases are exposed and pared with another strand of DNA by hydrogen bonds. It is also double helix where 2-sugar phosphate backbone form the DNA and are connected by the bases sticking out from the sugar molecules.

Question 44

What are base-pairing and complementary base?

Answer 44

Base-pairing are the 2 complementary base in the opposite direction on a same stick. The complementary bases are the pairing that never changes. C - G G - C T - A A - T

Question 45

What are the differences between DNA and RNA?

Answer 45

The DNA has 2 strands and is composed of CGAT. It stores genetic information (archive) and contains information of more than 1,000 genes. RNA has only 1 strand and is composed of CGAU. It directs production of protein based on DNA information and act as a working copy. It only contains information for one gene. RNA is a universal translator.

Question 46

What is transcription?

Answer 46

It is a working copy of the genetic information copied into RNA using the complementary base paring.