Quiz 1 Flashcards
(22 cards)
Define the term “chemical element”
A substance that cannot be broken down any further by chemical means
Specify the name and symbol for the four most common elements in the human body
- Oxygen (O
- Carbon (C)
- Hydrogen (H)
- Nitrogen (N)
What is the importance of the four common elements in the human body?
- All found in organic molecules
- N: in proteins and nucleic acid
- C: backbone organic molecules
Define the term molecule
The combination of two or more atoms
Define the term compound
A molecule containing at least two different elements
Define the term atom and describe its structure
The smallest unit of a chemical element that still retains the physical and chemical properties of that element.
- Consists of protons, neutrons and electrons
Describe the formation of an ion and an ionic bond
- When an element is stable and has a full valence shell
- Formed when two opposing charges are attracted to each other and transfer electron(s) to be stable
Describe the formation of a covalent bond
Atoms share electrons to achieve a stable valence shell.
What is the difference between an organic and inorganic molecule?
- Organic contains carbon
- Organic uses covalent and inorganic uses ionic bonds
Describe the composition of an organic molecule
- Large complex
-contain carbon
-covalent bonds
-carries out chemical reactions
Name two characteristic of organic molecules that make them useful to living organisms
- Sources of energy
-Perform chemical reactions - Carbon is an essential property of life
What are examples of organic molecules?
- Carbohydrates
- Lipids
- Amino acids
- Proteins
Specify the chemical properties of water
Two hydrogen and an oxygen covalently bonded (H20)
Explain the biological importance of water
- Lubricant and cushion
- A heat sink
- A universal solute
- Critical for chemical reactions
Specify the percentage of body weight that is composed of water
- Adult male 60%
- Adult female 50%
Estimate the amount of body water you contain in litres
42 litres
Describe the distribution of body water
- 55% intracellular fluid
- 26% interstitial fluid
- 16% plasma
- 4 % other fluid
Describe the chemistry of Carbon
- What makes an organic compound (skeleton)
- Uses a covalent bond (4 electrons in shell)
Describe the structure and function of carbohydrates
- Molecule composed of carbon, hydrogen and oxygen (1:2:1)
- Referred to as saccharides (sugars)
- Primary energy source
Describe the structure and function of lipids
- Made up of mostly hydrocarbons (non polar)
- Triglycerides: glycerol + fatty acids (fuel source when glucose low or fasting)
- Phospholipids: polar head, glycerol, non polar tail, structure of cell membranes
- Steroids: 4 hydrocarbon rings bonded with atoms and molecules. Component of bile, building block of hormones
Describe the structure and function of proteins
Composed of amino acids linked by peptide bonds. (amino group, carbon, carboxyl group). Functions: movement, framework, enzymes, transport, regulate fluid pH, regulate metabolism, defend the body
Describe the structure and function of nucleic acids
Composed of one or more phosphate groups, pentose sugar, nitrogen containing base. (DNA stores genetic information or RNA makes genetic code as a protein), hydrogen bond
