TERMS FOR UNIT 1 Flashcards
Define anabolic and catabolic
Anabolic: build complex molecules (ex: steroids build up muscles)
Catabolic: break down complex molecules (ex: catastrophe; destroy)
Define endergonic and exergonic
Ender: keep energy
Exer: release energy
Non-spontaneous vs spontaneous
Non-spontaneous: energetically unfavourable (won’t occur unless coupled with another rxn giving energy)
spontaneous: energetically favourable
What’s energy? What’s it dependant on?
Property of matter (ex: mass)
Dependant on the system where it’s used
When energy required to BREAK bonds is greater (>) than energy required to FORM bonds what do we call it?
Exergonic - energy released to surroundings
When energy required to BREAK bonds is less (<) than energy required to FORM bonds what do we call it?
Endergonic - energy taken up from surroundings
Redox rxns
oxidizing substance loses electrons in the reaction, and the reducing substance gains electrons
OX (-)
RD (+)
Where do organic fuel molecules come from?
Plants!
Photosynthesis energy > organic molecules (glucose) > cellular respiration uses glucose & H2O > producing H2O & CO2 > ATP produced
What’s phosphorylation?
attachment of a phosphate group to a molecule or an ion
What’s dephosphorylation?
removal of a phosphate group from an organic compound by hydrolysis
Metabolic pathways ____ ATP while Cellular respiration ___ ATP
require
provides
What are the stages of cellular respiration? Where in the cell do they occur?
1) Glycolysis - cytosol
2) CAC - mitochondrial matrix
3) Oxidative phosphorylation - inner mitochondrial matrix
What are the reactants and products of cellular respiration? What are the relative amounts?
Reactants: O2, glucose
Products: CO2, ATP and H2O
glucose + 6 O2 –> 6 CO2 + 6 H2O + 25 ATP
What is the difference between substrate-level phosphorylation and oxidative phosphorylation?
Substrate: ADP or GDP phosphorylated by substrate to produce ATP or GTP
Oxidative: phosphorylation of ADP to ATP using free energy from redox rxns in ETC
What are the products/substrates of oxidative phosphorylation?
Substrates: ADP, NADH, FADH2, O2, Pi (phosphate)
Products: ATP, NAD+, FAD, H2O
Where do fats and proteins enter the cellular respiration pathway?
Glycolysis
Where does the electron transport and chemiosmosis take place in prokaryotes and eukaryotes?
pro: plasma membrane
euk: inner mito. membrane
Quickly summarize cell-signalling
Cell receives signal external environment > responds w/ biochemical changes > affects function
What sort of ligand molecules would have receptor proteins in cell membrane?
Intracellular receptors, gated ion channels, G-protien coupled receptors, receptor tyrosine kinases
What sort of ligand molecules would have receptor proteins in the cell’ cytoplasm or nucleus?
A hormone receptor
Describe ion channels
- open/close depending on if ligand is bound to receptor
- in absence of ligand, no ions get through and gate is closed
- when ligand binds, shape change occurs
- inside is (-) and outside is (+)
How does transduction begin?
ligand binds to the receptor and causes a shape change
What are the transducers? Describe 2nd messengers?
proteins (enzymes), second messengers like cAMP, IP3 and Ca2+
they are polar, small, and diffuse quickly around the cell, participate in signal transduction
How does Ca2+ get back out into cell?
- Cells spend energy to keep Ca2+ out of the cell and store in the ER
- They get back out by gated ion channels on the ER, once IP3 binds, Ca2+ comes out
- this activates a particular cell response
What are the three possible responses?
- change in gene expression
- activation/inactivation of enzymes
- change in transport across membrane
Define monomer
Subunit
A molecule that can join with other identical monomers to form a larger structure called a polymer
Define polymer
large molecules consisting of repeating subunits
What are the four classes of large biological molecules?
Carbohydrates, proteins, nucleic acids and lipids
Define carbohydrates & give function
glucose monomers
fuel, building material
Define proteins & give function
amino acid monomers
diverse class of molecule, does anything to extent
Define nucleic acids & give function
nucleotide monomers
store, transmit, and express hereditary info
Define lipids & give function
fatty, waxy, or oily compounds that are insoluble in polar solvents such as water
fuel, membranes, steroids (hormones)
How do nitrogenous bases pair together? A, C, T, G
A and T* always together
C and G always together
*in RNA, A binds with U
Define saturated vs unsaturated lipids
Saturated: no double bonds, solid
Unsaturated: double bonds, liquid, etc
How does info get out of the nucleus and affect everything else?
- unwind molecule to expose bases
- read in groups of 3 to correspond to amino acid
- create polypeptide from string of amino acids
Describe the 4 protein structures.
Do all proteins have all structures?
1: string letters
2: interactions occur due to functional groups attached to those amino acids
3: 3D shape, long string
4: more tertiary structures formed together
All proteins only have 1 to 3 structure
List phases of mitosis in order
interphase, prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis
Define interphase
Chromosomes duplicate, and the copies remain attached to each other.
Define prophase
In the nucleus chromosomes condense and become visible. In the
cytoplasm, the spindle forms.
Define pro metaphase
The nuclear membrane breaks apart, and the spindle starts to interact with the chromosomes.
Define metaphase
The copied chromosomes align in the middle of the spindle.
Define anaphase
Chromosomes separate into two genetically identical groups and move to opposite ends of the spindle.
Define telophase
Nuclear membranes form around
each of the two sets of chromosomes, the chromosomes begin to spread out, and the spindle begins to break down.
Define cytokinesis
The cell splits into two daughter cells, each with the same number of chromosomes as the parent. In humans, such cells have two copies of 23 chromosomes and are called diploid.
Define autocrine and paracrine signalling
Autocrine signaling: targets itself, releasing a signal that can bind to receptors on its own surface.
Paracrine: targets a nearby cell (one not attached by gap junctions)
Define long-distance and synaptic signalling (also type of paracrine signalling)
Long distance: signaling molecules act on a target cell that is far from the signaling cell
Synaptic: nerve cells transmit signals at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells
Define hormonal signalling (also called endocrine signalling)
Mediates the synthesis of other hormones by stimulating their manufacture and release
What are the two types of passive transport (no energy needed)?
And what molecules travel by this transport?
1) diffusion across membrane - nonpolar molecules
2) facilitated diffusion (needs channel/carrier protein) - polar molecules
What’s active transport? What is needed for it? Give two examples.
substances move against the concentration gradient, from an area of low concentration to an area of high concentration
needs ATP and carrier protein
ex: sodium-potassium pump, cotransport of glucose and sodium
What’s cotransport? Define cotransporter?
transport of 1 molecule (glucose) made possible by transport of another molecule (Na+)
must transport 2 molecules at same time
Looking at intestinal epithelial cells…
Define apical side and basal side.
Apical: absorb as much glucose as possible from lumen (even if cytosolic is higher than lumen) - against gradient
Basal: pass glucose to extracellular fluid (where concentration is lower)
Why are tight junctions key?
- create barriers within membrane to keep transport proteins in appropriate ends
- barriers between lumen and basal facing end, prevent molecules drifting back to lumen
