Chapter 4: Chemical Composition in a Cell ( P2 ) Flashcards
What are the importance of carbohydrate in a cell?
- provide energy
- to build cell wall using cellulose
- to form external skeletons ( chitin ) of insects
- as energy storage in the form of glycogen in the liver and as starch in plant cells
Are proteins organic compounds?
- Yes and they are found in muscles, hair, and skin
What are the elements found in proteins?
- carbon
- hydrogen
- oxygen
- nitrogen
Are sulphur, phosphorus, and calcium found in most protein?
- No, only sulphur and phosphorus are found in most proteins
What are made up of polypeptide polymers?
- Proteins
What is the monomer for proteins?
- amino acids
How are amino acids joined?
- they are joined together by peptide bonds through condensation
When does a water molecule and dipeptide form?
- it is when two amino acids are joined by a single peptide bond through condensation
How are polypeptides formed?
- it is when many amino acids are joined together by peptide bonds to form a long chain of amino acids
How many types of amino acids are present in proteins?
- 20
What is the importance of protein in a cell?
- build new cells for growth
- regeneration
- to form connective tissues
- to form keratin in the skin
- synthesize of hormones
What is in first-class proteins?
- contain all amino acids
- animal proteins
Are lipid organic compounds?
- Yes and they are made up of long hydrocarbon chains
Elements found in lipids?
- Carbon, hydrogen, and oxygen but with a higher ratio of hydrogen to oxygen atoms
What are the properties of lipids?
- hydrophobic
- insoluble in water but soluble in organic solvents such as alcohol, ether, acetone, and chloroform.
- naturally formed in the body
Whats are the four types of lipids?
- fats
- waxes
- phospholipids
- steroids
Tell one difference between fats and oils?
- fats are solid at room.t because of their high melting points
- oils are liquid at room.t because of their low melting points
Which category are fats and oils placed in?
- triglycerides
Explain triglycerides.
- made up of one molecule of glycerol and three molecules of fatty acid
- involves condensation to form triglyceride and 3 molecules of water
What are the two main types of fats?
- saturated fats
- unsaturated fats
Compare and contrast saturated fats and unsaturated fats.
Similarities
- both are lipids that contain carbon, hydrogen, and oxygen
- both are insoluble in water
Difference ( saturated )
- solid at room.t
- increases blood cholesterol
- only single bonds between carbon atoms
- Ex: Butter and full cream dairy products
Difference( unsaturated )
- liquid at room.t
- decreases blood cholesterol
- at least one double bond between carbon atoms
- Ex: Olive oil and fish
Explain waxes.
- naturally occurring lipid
- one molecule of alcohol and one molecule of fatty acid
- high melting point and insoluble in water
- candles
Explain steroids.
- include sex hormones and cholesterol
- insoluble in water
What is the importance of lipids in cells?
- produce bile
- synthesize steroid hormones
- protect organs by acting as a heat insulator
- as a solvent for vitamin A, D, E, and K
What are nucleic acids?
- organic molecules consisting of polynucleotide
Other than carbon and hydrogen, what are the elements found in nucleic acids?
- oxygen
- nitrogen
- phosphorus
Explain the structure of nucleotide?
- consists of a pentose sugar ( 5-carbon sugar ), a nitrogenous base, and a phosphate group
- four types of nitrogenous base: adenine(A), thymine(T), guanine(G), and cytosine(C)
Explain the structure of DNA.
- made up of millions of nucleotides to form a polynucleotide
- sugar and phosphate chain forms the backbone of DNA
- DNA molecule consists of two polynucleotide chains intertwined in opposite directions
