Exam 1 Flashcards
What is an explanation for a phenomenon that is based on observations and prior knowledge, and that must be tested experimentally in order to accept or reject?
hypothesis
Triglycerides are ______.
lipids
The oxygen of a water molecule:
- is bonded covalently to two hydrogen atoms
- contains a partial negative charge
- is weakly bonded to hydrogens of other water molecules
A hydrogen ion concentration of 10^-7 mol/liter is equivalent to a pH of ___.
7.0 pH
Which compound is hydrophobic?
- CH3CH2OH
- glucose
- CH3CH2[CH2]10CH3
- glycerol
- CH3CH2[CH2]10CH3
The formation of large biomolecules from small monomers is accomplished by what kind of reaction?
condensation
The important structural difference between a molecule of starch and a molecule of cellulose is that _____.
in cellulose, the glucose units are bonded by beta linkages
Phospholipids are molecules that contain:
hydrophilic heads and hydrophobic tails
An -OH group is a ____ group.
hydroxyl group
Enzymes are examples of _____ proteins.
globular
What is the basic unit of proteins?
amino acids
What is the basic unit of DNA?
nucleotides
What is the basic unit of RNA?
nucleotides
What is the basic unit of cellulose?
glycerol
What is the basic unit of glycogen?
glucose
What is the basic unit of starch?
glucose
What are the two basic building blocks of structural lipids?
fatty acids and glycerol
What is the monomeric subunit unit of proteins?
amino acids
What are lipids?
- mostly hydrogen and carbon
- NONPOLAR, or amphipathic (insoluble in water)
- Fats, phospholipids, steroids, waxes
What are the functions of lipids?
- Long term energy storage
- Structural purposes within the cell
- Cell-signaling purposes
- Protection
- Insulation
- Prevention of water loss
What’s so great about carbon?
- Stability
- Solubility
- Variability
What are monomers?
- Subunits or building blocks
What are polymers?
Monomers joined to form long chains
What are condensation reactions?
Condensation reactions form polymers
- DEHYDRATION SYNTHESIS (protein synthesis)
- covalent bond formation between monomers
- Water is released in the formation of covalent bonds
What are hydrolysis reactions?
Breakage of covalent bonds (polymers) between monomers
- Water is coming in to break apart covalent bonds
- one monomer is broken down at a time
What are the 5 biomolecules?
- Nucleic Acids
- Proteins
- Lipids
- Carbohydrates
T/F: A glycosidic bond is a non-covalent linkage
False: It always forms a covalent bond between monomers
What is starch?
Energy storage molecules that are found in plants
What is glycogen?
Energy storage molecules that are found in animals
What is cellulose’s main function?
STRUCTURE
What are fats?
- Also known as triglycerides
- Formed by bonding glycerol to 3 fatty acids
- Joined by dehydration’ broken apart by hydrolysis
What is the difference between an unsaturated fat and a saturated fat?
- Unsaturated fats are moving constantly, more likely to be in liquid form (kink in chain, more healthier)
- Saturated fats are tightly packed, most likely going to be a solid at room temperature
What are phospholipids?
Lipid bilayer
- Glycerol
- two fatty acids
- phosphate group
What are the polar heads on the lipid bilayer?
- hydrophilic (water-loving)
What are steroids?
- Four interconnected rings of carbon atoms
- Usually insoluble in water (cholesterol)
- Used in cell signaling
What is amphipathic?
hydrophobic and hydrophilic groups
Function of pili?
- allows exchange of genetic material (DNA) between bacteria
- allows bacteria to attach to surfaces and to each other
What is the function of the flagella?
- allows certain bacteria to swim
- motility
What is catabolism?
breaking down of molecules
- coordinated in the cytosol
What is anabolism?
- building/synthesizing biomolecules
What does the cytoskeleton do?
- provides shape, organization, and movement
What do microtubules do?
- provide shape and organization
- heavily involved in cell division
- help with motility
What do the intermediate filaments do?
- important for cell shape
- provide mechanical strength
What do the actin filaments do?
- involved in muscle contration
- cell shape, cell movement
What are cilia?
- often much shorter than the flagella
- tend to cover all or part of the cell surface (fuzzy)
What does the nucleolus do?
Ribosome assembly
What does the smooth ER do?
- detoxification
- lipid synthesis
- plasma membrane components
What does the golgi apparatus do?
- packaging and shipping center
- FedEx of the cell
- Proteins mature here
