Bio 2 exam 1 Flashcards
Catabolic pathways
involve the breakdown of nutrient molecules (food: A, B, C) into usable forms (building blocks). In this process, energy is either stored in molecules for later use, or released as heat.
Anabolic pathways
build new molecules out of the products of catabolism, and these pathways typically use energy. The new molecules built via anabolic pathways (macromolecules) are useful for building cell structures and maintaining the cell.
Lipids
- Energy storage
- Protective membranes
- Communication
Carbohydrates
- Energy storage
- Structural support
- Communication
Nucleic Acids
Contains genetic information.
Proteins
- Communcation
- transport
- Chemical Breakdown of substances
- Structural support
Most macromolecules are polymers
Polymers consist of many similar or identical building blocks linked by covalent bonds.
– the repeating building blocks are small molecules called monomers
Biopolymers are made by condensation reactions
Condensation (also known as dehydration) reaction
- Monomers connected together a covalent bond
- Water is lost in the process
- Energy is required
- Special enzymes are needed
4 macromolecular
carbohydrates (polysaccharides), lipids (or fats), proteins, and nucleic acids.
cohesion
Water molecules form hydrogen bonds with each other, resulting in an attractive force
adhesion
Polarity also allows water to attract other polar molecules
Carbohydrates
Include both sugars and the polymers of sugars
Most names for sugars end in -ose.
Sugar molecular formulas are generally some multiple of CH2O
Polysaccharides serve two primary functions
energy storage and structural support
The primary energy storage polysaccharide in plants is starch. Animals (and some fungi) store glucose as glycogen.
The primary structural polysaccharide in plants is cellulose.
Starch, glycogen and cellulose are all polymers of glucose
Glycogen location
In humans, glycogen is made and stored primarily in the cells of the liver and the muscles.
glycogen phosphorylase
when glucose is needed for energy, glycogen is broken down and converted again to glucose by an enzyme
Alpha
OH on bottom
Beta
OH on top
Starch location
Plants store surplus starch as granules within chloroplasts and other plastid
Amylose vs Amylopectin
Simple (unbranched) AMYLOSE and complex (branched) AMYLOPECTIN
amylases
an enzyme that converts starch and glycogen into simple sugars.
Chitin builds the cell wall of fungi and the exoskeleton of arthropods
Lipids
- Consist of C, H, and O
- Not true polymers
– Composed of glycerol
and fatty acids - Fatty acids
Most fat storage in animals is in the form of triacylglycerides
Triacylglycerides are made of three fatty acids covalently bound to a glycerol molecule
unsaturated triglycerol
molecules prevents them from packing tightly together
Omega fatty acids
- Omega fatty acids are essential fats
– Our bodies can’t produce them - the only source is food
– Used for building healthy cells and maintaining brain and nerve function - Growing evidence that they help lower the risk of heart disease
- Two main types: Omega-6 and Omega-3
– Omega-6 mostly comes as linoleic acid from plant oils such as corn oil, soybean oil, and sunflower oil, as well as from nuts and seeds
– Omega-3 come primarily from fatty fish such as salmon, mackerel, and tuna, as well as from walnuts and flaxseed in lesser amounts
Animals store fats in adipose tissue
– means of storing metabolic energy over extended periods of time
– also serves to insulate organisms and protect organs
lipolysis
when muscles and other tissues need energy, certain hormones bind to adipose cells and trigger the hydrolysis of triacylglycerol, resulting in the release of energy-rich fatty acids and glycerol
prostaglandins
hormone-like substances involved in regulating blood pressure, tissue inflammation, and contracting and relaxing smooth muscles
Phospholipids
are derivatives of triacylglycerols with a phosphate group. They are major components of all cell membranes.
Lipoproteins
transport lipids and steroids in the body
Hyperlipidemia
Group of lipid metabolism disorders that involves abnormally elevated levels of lipids in the blood
– Lipoprotein transport disrupted
why are fats important?
- Provide energy
- Metabolized to provide essential molecules for normal cell biochemistry
- Build healthy cells and healthy bodies
– also are important in insulation of nerve cells to improve nerve impulse conduction - Help the body use and transport vitamins
- Make hormones
- Help regulate temperature
- Provide protective cushion to organ
