Unit 1 - Biochem Flashcards
Carbohydrates - Building Blocks
Monosaccharides which are simple sugars
Carbohydrates - Use
energy, structure, and for storing/transporting energy
What do animals store glucose as? What do plants store glucose as?
Animals store glucose as glycogen which is a carbohydrate
Plants store glucose as starch which is a carbohydrate
Carbohydrates - Structure
- Made up of only carbon, hydrogen, and oxygen MUST be in a 1:2:1 ratio
- Monosaccharides (single rings), disaccharides (double rings)
Monosaccaride
Simple sugars, serve as a major nutrients for cells and as raw material for building carbohydrates
Polysaccarides
Polymers. Also known as complex carbs, since they contain many monomers. Have storage and structural roles. The structure and function of a polysaccharide are determined by its sugar monomers and the positions of glycosidic linkages (sugar and another molecule). Can be branched or in straight chains.
Disaccharide
Two monosaccharides bonded together. A disaccharide is formed when a dehydration reaction joins two monosaccharides. This covalent bond is called a glycosidic linkage.
Cellulose
Carbohydrate. Made of repeating monomers of glucose. Make up cells walls in plants - structure. Does not dissolve in water, and is not easily broken down because it has so many links. Most herbivores require special bacteria in their gut to digest cellulose.
Chitin
Carbohydrate. Similar to cellulose. Forms chains linked by hydrogen bonds. Forms structural materials. Durable, translucent, and flexible. Strengthens hard parts of animals like insects and arachnids. Forms the cell walls in fungi.
Starch
Carbohydrate. Different covalent bonding patterns between glucose monomers makes a chain that can coil up into a spiral. Not very soluble in water, but more unstable than cellulose. Ideal for storing glucose in plants, but cannot be transported easily- must be broken up first. Humans have enzymes that can break down starch
Glycogen
The covalent bonding pattern in this molecule produces a highly branched polysaccharide. The sugar storage molecule in animals. Stored in muscle and liver cells. Can be broken down to access glucose for energy.
Amphipathic (meaning and why its important)
Amphipathic means both hydrophobic and hydrophilic parts. In a phospholipid, the amphipathic nature is crucial for its function in forming biological membranes. The polar head is hydrophilic, meaning it is attracted to water, while the nonpolar tails are hydrophobic, repelling water. This dual characteristic allows phospholipids to form a bilayer in aqueous environments, like the cell membrane. The hydrophilic heads face outward, interacting with the watery environments inside and outside the cell, while the hydrophobic tails face inward, away from water, forming a stable barrier. This arrangement is essential for regulating what enters and exits the cell, maintaining its selective permeability.
Lipids - Structure
Made of carbon, hydrogen, and oxygen. Sometimes phosphorus.
Fatty acids are composed of both polar and nonpolar regions, leading to both hydrophilic and hydrophobic properties
Hydrocarbon “tails”: hydrophobic (nonpolar)
Carboxyl group “head” : hydrophilic (polar)
Fatty Acids: Simple organic compounds with a carboxyl group joined to 4 to 36 carbon atoms
Does NOT have 1:2:1 ratio (way more carbons than oxygens)
Glycerol attched to each carboxyl group of each fatty acid tail
Lipids - Use
long term energy storage, structural foundation of cell membranes
Lipids - Building Blocks
Glycerol and fatty acids
Lipids - Saturated vs Unsaturated
Saturated fatty acids: have the maximum number of hydrogen atoms possible and no double bonds, flexible and can stack up at room temperature, forming a solid. The absence of carbon-carbon double bonds in molecules, such as in saturated fats, allows them to pack closely together. Ex: animal fat
Unsaturated fatty acid: have one or more double bonds in the hydrocarbon tail, less flexible due to bend and cannot stack together. The double bonds have to be in the hydrocarbon tail for it to be unsaturated. Forms a liquid ex: vegetable oil
Steroids
Lipids with a rigid backbone of four carbon rings and no fatty acid tails, The most common steroid in animal cell membranes (helps maintain cell structure). Forms bile salts that help us digest fats, forms vitamin D which is needed by bones and teeth, steroid hormones like estrogen and testosterone which govern reproduction and reproductive system development. Steroids can be recognized by their multiple rings of carbon atoms connected together. Steroids are included in lipid category because they are also hydrophobic and insoluble in water.
Waxes
Lipid. Complex molecules with a varied mixture of lipids with long fatty acid tails bonded to long chain alcohols or carbon rings, molecules pack tightly, so wax is firm and water resistant. Generally solid at room temp.
Phospholipid
Molecules with a polar head containing a phosphate and two nonpolar fatty acid tails, Head = polar + hydrophilic, Tails = nonpolar + hydrophobic, most abundant lipid in cell membranes. Phospholipids make up the semipermeable membrane of the phospholipid bilayer.
Triglyceride
A lipid. The carboxyl group of a fatty acid easily forms bonds with other molecules. 3 fatty acids attach to glycerol via the carboxyl group, which then loses its hydrophilic properties. The new molecule is hydrophobic and does not dissolve easily in water. They are the most common type of fat in your body. Circulate in your blood.
Trans Fats
The arrangement of hydrogens around the carbons have a significant effect on our bodies ability to process the lipids. Trans fats are difficult for our body to break down leading to its health dangers, made through hydrogenation of oils
Proteins - Use
Structure, nutrition, enzymes, transport, communication, cellular defense
Proteins - Structure
Made of amino acids: amine group, a carboxyl group, and an R group
The R groups (or functional groups) give the amino acid unique properties, like being polar, non-polar, acidic, etc.
Consists of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.
Lots of oxygen + nitrogen in R group made a protein polar
If it just has carbon and hydrogen in the R group then there is nothing pulling the electrons strongly so it is nonpolar
If it has sulfur, it is special. Sulfur is polar but its not that strong so it still makes it nonpolar
S-S bonds are nonpolar and lead to more stability
Protein structure is important because the structure of the protein determines its function
Proteins - Building Blocks
Amino acids