Week 1- Molecular Basis of Living Systems

Question 1

What are the basic properties of a cell

Answer 1

Cells are alive
Cells are highly complex and organized
Cells carry genetic information
Cells reproduce by division
Cells carry out metabolism
Cells respond to stimuli

Question 2

Cell are highly complex and organized

Answer 2

Cells have consistent structures
Cells possess organelles
Organelles have distinct functions
Organelles consist of polymers
Polymers consist of building block molecules

Question 3

Examples of Polymers Vs building block molecules

Answer 3

Nucleic Acid Vs Gene
Amino Acid Vs Protein

Question 4

Cells carry genetic information

Answer 4

Cells contain nucleus
Nucleus contains chromosomes
Chromosomes contain genes
Genes contain specific information on cellular activities

Question 5

Cell reproduce by division

Answer 5

Division: Content of one mother cell is distributed to two daughter cells
Genetic information is copied before division
Each daughter cells receives one copy of the duplicated genetic information

Question 6

Cells carry out metabolism

Answer 6

Cells maintain complexity and structure by consuming energy
Energy is generated by metabolism
Cells carry out metabolism

Question 7

Cells respond to stimuli

Answer 7

Cells respond to stimuli through receptors
Stimuli includes growth factors, hormones, chemicals and etc
Receptors are linked to a specific intercellular signalling cascade
Cascade determines cellular respond to stimuli
Responses include movement and division

Question 8

Organelles of Eukaryotes

Answer 8

Mitochondria: generates energy
Endoplasmic reticulum: manufactures lipid and proteins
Golgi complex: transports materials to a specific location
Lysosome: Digest macromolecules to recycle

Question 9

Nature of Biological Molecules

Answer 9

Hydrocarbons are the simplest organic molecules
Functional groups are found to replace hydrocarbon groups in many organic molecules important in biology
Functional groups include hydroxyl groups, carboxyl groups, sulfhydryl groups and amino groups

Question 10

What are macromolecules

Answer 10

Form structures and carry out cellular activities such as protein, genes, polysaccharides

Question 11

What are macromolecule building blocks

Answer 11

Most macromolecules have a short lifetime compared with cell (turnover of building blocks)

Question 12

What are Metabolites

Answer 12

Intermediates of metabolic reactions

Question 13

Molecules of miscellaneous function

Answer 13

Vitamins
Hormones
Energy storage (ATP)
Regulatory (cAMP)

Question 14

Four types of Biological Molecules

Answer 14

Lipids
Nucleic Acid
Carbohydrates
Proteins

Question 15

Carbohydrates

Answer 15

They are diverse macromolecules
Like monosaccharides like glucose
And Glycogen which is used for short term energy storage

Question 16

Lipids and Fatty Acids

Answer 16

Long term energy storage form
One glycerol linked (condensation reaction) to three fatty acids (triacylglycerol)
Fatty acids may be different in composition (saturated or unsaturated)
Hydrophobic Long carbon chain
Hydrophilic COOH head
Stored in adipocytes

Question 17

Proteins - General Information 1

Answer 17

Macromolecules with 20 amino acids as building blocks
Protein structures are specific and their function are unique
Carry out all cell activities
Enzymes influence metabolic reactions
Cytoskeletal elements provide structural support
Receptors determine cell responses
Motor protein are basis for movement
Antibodies constitute part of immune system

Question 18

Proteins- General Information 2

Answer 18

Each amino acid has central C with 4 attached groups
2 attached groups are NH2 and COOH
Protein Synthesis links NH2 of one a.a to COOH of another a.a
R group determine inter and intra-molecular interaction and protein activity

Question 19

Nucleic Acids

Answer 19

Mainly involved in storage and transmission of genetic information
Nucleic Acids consist of 3 groups - phosphates, sugar and base
DNA has a deoxyribose
RNA has a ribose
Purines consist of 2 rings and include adenine and guanine
Pyrimidines consist of 1 ring and includes cytosine and thymine (Uracil in RNA)
ATP provides energy
GTP provides cell signaling

Question 20

Chemical Basis of Cells - Summary

Answer 20

Biological Molecules includes - carbohydrates, lipids, proteins and nucleic acids
Carbohydrate consist of macromolecules of sugar and is involved in short term energy storage
Lipid Molecules are hydrophobic and hydrophilic and involved in long term energy storage
Protein carry out most cell activities, consist of amino acids and have different levels of structure
Nucleic acids mainly involved in genetic information and consist of purines and pyrimidines