Download Introduction to 9th Grade Biology

Introduction to 9th Grade Biology
Biomolecules
Classes of Biomolecules
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Carbohydrates
Lipids
Proteins
Nucleic Acids
Carbohydrates
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Monosaccharaides (simple)
Glucose- Found in Honey
Fructose – Fruit!
Galactose – Found in Milk
Disaccharides (complex)
Sucrose – Table Sugar
Lactose – Milk Sugar
Maltose – Found in Seeds, grains
Lipids
• Our body needs them for insulation,
cushioning, and energy storage.
• Three important groups
– Fats & Oils
– Phospholipids (cell membrane)
– Steroids (cholesterol)
Structure of Fatty Acids
• Long chains of mostly carbon and hydrogen atoms
with a -COOH group at one end.
• When they are part of lipids, the fatty acids
resemble long flexible tails.
Saturated and Unsaturated Fats
• Unsaturated fats :
– liquid at room temp
– one or more double bonds between carbons in the
fatty acids allows for “kinks” in the tails
– most plant fats
• Saturated fats:
– have only single C-C bonds in fatty acid tails
– solid at room temp
– most animal fats
Phospholipids
• Structure: Glycerol + 2 fatty acids + phosphate group.
• Function: Main structural component of membranes, where they
arrange in bilayers.
Phospholipids in Water
Steroids
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Structure: Four carbon rings with no fatty acid tails
Functions:
Component of animal cell membranes
Modified to form sex hormones
Steroid ring structure
• The common structural feature of steroids is that
their molecules contain the following ring skeleton.
Proteins
• Combination of 20 amino acids
• Functions
– Structure
– Transport
– Hormones
– Cell identification & communication
– Metabolism
Amino Acid Structure
Amino Acid Structure
• Amino Group- NH2
• Carboxyl Group- COOH
• R Group/Side Chain- blank space that
determines the type of amino acid
Nucleic Acid
• Three important Nucleic Acids
– DNA- Genetic Code, working instructions for the
cell. Stores genetic information. (double stranded
with a Double Helix shape like a 3-D twisted
ladder) [Deoxyribonucleic Acid]
– RNA- transfers the genetic information (single
stranded) [Ribonucleic Acid]
– ATP- Provides energy for all cells
Nucleotide – monomer that makes up nucleotides. Consists
of a pentose molecule, a phosphate molecule and a nitrogen
base
• ribose molecule – a 5-carbon sugar (pentose)
• phosphate group – an ion of 1 phosphorus
and 4 oxygen
• nitrogenous base – nitrogen containing ring
structures.
• Purines – adenine (A) and guanine (G)
• Pyrimidines – cytosine (C), thymine (T) and uracil (U)
– (note: A and T form pairs while G and C form pairs in DNA
but in RNA T is replaced with Uracil and so U pairs with T)
Nucleotide Structure
Pyrimidines are single ring nitrogen bases
• Notice that Thymine, Cytosine and Uracil are
your pyrimidine nitrogen bases.
Purines are double ring nitrogen bases
• Notice that Adenine and Guanine are your
purines nitrogen bases.