*random biology flashcards*
Intramolecular forces
strong attractive forces that hold atoms within a molecule
Intermolecular forces
exist between molecules
True or false: intramolecular forces are far weaker than intermolecular forces
False - intramolecular forces are much stronger
Intermolecular forces are significant because:
they determine physical properties such as boiling point, melting point, density, etc.
empirical formula for carbohydrates
(CH2O)n
How would we label a ringed sugar that has its hydroxyl group pointing down?
Alpha. OH is trans to the CH2OH group
Whenever a carbohydrate attaches to another molecule, it forms a _____ bond
glycosidic
sucrose
glucose + fructose
maltose
two glucose
lactose
galactose + glucose
what is cellulose
structural polysaccharide found in plant cell walls, wood, paper
cellulose contains ___ linkages which form ____ strands
B-1,4 (beta 1,4); linear
True or false: cellulose is a highly rigid structure
True. Due to B-1,4 linkages to pack strands linear and parallel (due to H bonding between adjacent strands)
True or false: humans cannot digest cellulose
True. It passes through our digestive tracts as fiber
proteome
all of the proteins expressed in a cell
genome
all of the dna in a cell
amino acids form peptide bond with each other via:
dehydration/condensation reactions
What is hybrid sterility?
when a hybrid zygote is sterile and cannot reproduce
Behavioral isolation occurs when:
different species do not perform the right type of mating rituals, hence preventing mating
Gamete isolation
occurs when gametes from different species do not recognize and thus cannot fertilize each other
Hybrid mortality
a hybrid zygote dies before reaching a reproductive age
Hybrid F2 breakdown
when the second generation of hybrids suffer from decreased fitness
Postzygotic isolation includes:
Hybrid mortality, hybrid F2 breakdown, hybrid sterility
Semelparity
describes the animals that only mate once in their entire life; produce many offspring from their single “reproductive episode;” however, the babies they make have a low chance of surviving to adulthood
Starch function
form of energy storage in plants
What type of bonding is found in starch
alpha bonded
Linear starch is known as
amylose
Branched form of starch is called
amylopectin
Glycogen
form of energy storage in humans
What type of bonding is found in glycogen
alpha bonded
True or false: glycogen has more branching than starch
true
What is the most abundant polysaccharide found in fungi cell walls?
Glucans
what does the cell theory say?
- living things contain one or more cells, cell is the basic unit of life. 2. new cells must arise from pre-existing cells
cell membranes contain:
phospholipids, cholesterol, proteins
what are phospholipids made of?
- 3-carbon glycerol backbone
2. attached to one phosphate group and two fatty acid tails
Because phospholipids are amphipathic, they:
spontaneously self-assemble into a bilayer when in an aqeuous environment
cholesterol makes up around __-__% of a eukaryotic cell membrane
30-50%
cholesterol contains:
4 hydrocarbon rings
cholesterol is a precursor to:
steroid hormones
Membrane proteins come in 2 types:
integral and peripheral
integral proteins
aka transmembrane proteins, they traverse the entire phospholipid bilayer
true or false: interal proteins are hydrophilic
false: they are amphipathic since they contact both polar and nonpolar parts of the cell membrane
peripheral membrane protein
do not extend throughout the whole membrane. could mean the polar heads of the phospholipid bilayer, partially inserted into the membrane, or attached to one of the hydrophilic surfaces of an integral membrane protein.
true or false: peripheral membrane proteins are generally hydrophilic
true
integral proteins may function in cell signaling, but most tend to function in ____
transport
transport proteins function
move large, polar molecules across the cell membrane since they cannot freely diffuse by themselves
Receptor proteins are:
can be both integral or peripheral membrane proteins
receptor proteins function
receive chemical signals from the extracellular environment that need to be transmitted inside the cell, triggering secondary responses
peripheral membrane proteins functions
adhesion proteins, cellular recognition proteins, receptor proteins
adhesion proteins
attach adjacent cells to other thins like other cells, also act as anchors for the cytoskeleton
What is the main function of Schwann cells?
A. Produce nutrients for nuclei in the spinal cord
B. Provide blood supply to glial cells
C. Secrete CSF for the brain
D. Contributes to the blood brain barrier
E. Form myelin sheath in neurons
E. Form myelin sheath in neurons
Schwann cells are part of:
peripheral nervous system
Schwann cells form the:
myelin sheath
What is myelin sheath?
fatty insulation of axons in neurons
Oligodendrocytes form the ____ ____ in the ___ ___ ___
myelin sheath; central nervous system
Astrocytes provide:
blood supply and nutrients to the CNS neurons including neurons in the spinal cord
Astrocytes contribute to:
the blood brain barrier
Satellite cells provide:
blood supply to the PNS neurons
Which cells create cerebrospinal fluid?
Ependymal cells
In the vertebrate nervous system, the term “Node of Ranvier” refers to:
the gap between the myelin sheath segments
The gap between the axon terminal and dendrite of the next neuron is called the:
synaptic cleft
the myelin sheath covers segments along the axon called:
internodes
In what part of the integumentary system are hair follicles’ erector pili muscles?
Dermis
What is contained in the dermis
hair follicles and erector pili muscles
Function of erector pili muscles
erect hair (goosebumps) and play roles in temp regulation and scaring off predators in some mammals
All of the following statements about low-density lipoproteins (LDLs) and high-density lipoproteins (HDLs) are correct EXCEPT ONE. Which one is the EXCEPTION?
A. LDLs have low protein density while HDLs have high protein density
B. LDLs decrease glucose breakdown while HDLs increase glucose breakdown
C. LDLs are considered unhealthy while HDLs are considered healthy
D. LDLs deliver cholesterol to tissues while HDLs deliver cholesterol to the liver
E. LDLs are not involved in bile production while HDLs stimulate bile production
B. LDLs decrease glucose breakdown while HDLs increase glucose breakdown - LDL/HDL have no role in glucose breakdown
All of the following are characteristics of the desert terrestrial biome EXCEPT one. Which one is the EXCEPTION? A. Cold nights B. Very little rain C. Hot days D. Season fires E. Extreme weather fluctuation
D. Season fires
Seasonal fires are characteristic of:
savanna terrestrial biome
Which of the following is the most direct effect of removing peripheral chemoreceptors? A. Unregulated breathing B. Weakened blood brain barrier C. Increased heart rate D. Lowered blood oxygen concentration E. Decreased blood proton levels
A. Unregulated breathing
For Rho-dependent termination, at which point along the DNA is transcription forced to pause?
Transcription stop point