Upload
aminia
View
99
Download
8
Embed Size (px)
DESCRIPTION
Oils, fats and waxes. Waxes: Composed by long Carbon and Hydrogen chains that are highly hidrophobic. They are saturated. Are found in: hair, insect skeletons, leaves, stems and beehives. FIGURE 3-12b Lipids. Bees build their homes with wax hexagons. . Phospholipids. - PowerPoint PPT Presentation
Citation preview
Oils, fats and waxes
• Waxes:• Composed by long Carbon and Hydrogen
chains that are highly hidrophobic.• They are saturated.• Are found in: hair, insect skeletons, leaves,
stems and beehives.
FIGURE 3-12b Lipids. Bees build their homes with wax hexagons.
Phospholipids
- Are found in cell membranes.
Structure:2 fatty acids + glycerol + phosphate group + 1 functional polar group
FIGURE 3-15 Phospholipids.
Cabeza polar (hidrofílica)
Columna vertebral de glicerol
Colas de ácido graso (hidrofóbica)
Phospholipids
• They have hydrophobic and hydrophilic portions.– Polar “heads”: water soluble.– Non polar “tails”: not water soluble.
•Hydrophilic = lipophobic•Hydrophobic = lipophilic
Steroids
• They consist in 4 fusioned carbon rings.• Examples:
– Cholesterol• Found in animal cell membranes.
– Masculine and Femenine hormones.
Cholesterol
Estrogen
Testosterone
What are proteins?
Functions :– They are formed with amino acid chains.– Aminoacids join to form chains by dehydration
synthesis.– A protein can have 1,2,3 or 4 structure levels.– Enzimes catalize (speed up or accelerate)
reactions.– Elastin provides suport.
FIGURE 3-17a Structural proteins. Exaples: queratin, found in: a) hair b) horns c) spider silk.
Proteins´s functions
Function ExampleStructure Collagen in the skin and
keratin in hair.Movement Actin and myosin in the
muscles.Defense Antibodies in blood.Storage Albumin in egg white.Signals Growth hormone in blood.Catalysis Enzymes (EX: amylase
digests carbohydrates)
• Proteins are composed of amino acids.
• Aminoacids are proteins´s main units.
• They all have amino and carboxyl groups.
• They all have an “R” group:• Some are hydrophobic.• Some are hydrophilic.
Proteins
FIGURE 3-18 Amino acids structure.
Aminogroup
Hydrogen
“R” group
Carboxylgroup
FIGURE 3-19a Amino acid diversity.
• The amino acid sequence determines the properties and functions of every protein.
Amino acids
Dehydration synthesis
• Process by which amino acids join to form chains.
• The covalent bond that is formed between the C and the N is called peptide bond.
• The long amino acid chains are called polypeptides or proteins.
FIGURE 3-20 Protein synthesis.
4 structure levelsThe primary structure is the amino acid sequence that
forms the protein.
The secondary structure is composed of helix and chains that fold.
The tertiary structure consists in one complex peptidic chain that holds the structure with different links.
The quaternary structure is found where several proteic chains link.
Structure example: hemoglobin.
This folded plate is an example of the secondary proteic structure.
Hydrogen Links
Folded plate
FIGURE 3-23 Queratin structure.
queratin
Tridimensional structures
• The kind, position and number of amino acids determine the protein´s function.
– If bonds or links break, that causes the denaturing of the protein and lost of its biological functions.
FIGURE 3-24 Desoxyrribose nucleotide.
• There are 2 kinds of nucleotides:
– Ribose nucleotides:– The ones that contain: Adenine, Guanine,
Cytosine, Uracil. They are found in RNA.
– Deoxyrribose nucleotides:– The ones that contain:Adenine, Guanine,
Cytosine, Thymine. They are found in DNA.
– DNA• It spells the genetic info necesary to build proteins.
– RNA• Are DNA copies or replicas used at the protein
synthesis.
Inheritance molecules
FIGURE 3-25 Nucleotide chain.
base
sugar
phosphate
Hydrogen links
Other nucleotides
• AMP carries chemical signals inside the cell.
• ATP carries energy.
• NAD+ and FAD carry electrons.
ATP