quiz 1 SLOs BIO 152

Biological molecule

Molecules with carbon as its backbone, made by living organism

Monomer

Smallest unit of biological molecule, single LEGO piece

Polymer

Molecule made of lots of monomers bonded together into macromolecules

Hydrophilic

Water loving

Hydrophobic

Water fearing

Saturated

Max number of bonds hanging off carbon backbone is bonded to hydrogens, forms straight lines

Unsaturated

Form double bond or ring, forms kinked chains

Hydrocarbon

Carbon backbone dominated with hydrogen bonds

Metabolism

Overall sum of input and release of energy in a cell

Anabolic

Rxn needs net input energy

Catabolic

Rxn releases more energy than consumed

Activation energy

Amount of energy that must be added to a Rxn to get Rxn to proceed/start

Substrate

Raw ingredient for rxn

Product

What’s created by rxn

Intermediate

Temporary molecule that is no longer the substrate but is not in finished product, something in between

Enzyme

Background molecule that helps speed up rxn, not consumed (what comes in is what comes out)

Inhibition

Decrease/stop activity of an enzyme

Activation

Turning on ability of an enzyme to carry out a chemical rxn

Allosteric

Binding of a molecule to a protein at a site other than the active site and influences the activity of the protein

Cell membrane

Phospholipid bilayer structure that separates different water based compartments

Intercellular

Inside cell

Extracellular

Outside cell

Amphipathic

Two distinct chemically different regions on the same molecule

Fluidity

Ability of molecules in plasma membrane to move around

Permeability

Measure of how easy it is for molecules to move across a membrane, dependent on membrane structure

Selectively permeable

Only some molecules can move across membrane, allows cells to set up specialized environments

Solute

Molecules in watery environment

Solvent

Liquid component used to dissolve molecules and allow them to move around

Solution

Solute + solvent

Diffusion

Movement of a solute from high concentration to low

Net diffusion

Difference between gradient concentration moving a solute in one direction vs movement in opposite direction

Concentration

Mass of solute/mass of solvent

Osmosis

Net diffusion of water across a membrane

Passive

No extra energy cost to the cell to get solute to move

Active

Costs cell energy to move from high concentration to low

Facilitate

Protein helper involved in movement across membrane

Tonicity

Relative movement of water across a membrane and its effect on the volume of a cell

Crenate

Volume of cell has decreased below normal

Lyse

Cell membrane has ruptured

Turgid

Normal cell size

Cytoplasm

Jelly like substance that fills a cell and is enclosed by cell membrane

Cytoskeleton

Interlinks protein fibers and tubules that extends throughout the cytoplasm, provides structural support

Endomembrane system

Exchange material between intracellular structures within a eukaryotic cell

Endocytosis

Movement of material into the cell in bulk

Exocytosis

Movement of material out of the cell in bulk

Genome

Collection of genetic material passed from parent to offspring

Carbohydrates

Carbon backbone with groupings of hydrates

Function : store energy long term, break bonds into smaller pieces to get energy, and structural support

Lipids

Hydrophobic, generally neutral, structure usually dominated by hydrocarbons

Function : long term energy storage

Protein

Made of long chain of amino acids, nitrogen containing carboxyllic acid group

Function : many, mainly transportation

Nucleic acid

Made of nucleotide monomers, hydrophilic due to phosphates

Ex: DNA, ATP

How is carbon chemically the backbone of biological molecules

Carbon can make 4 strong covalent bonds with itself and other elements making it a good backbone for biological molecules. Carbon to carbon bonds are very strong

Enzymes

Enzymes lower AE of a rxn without changing the free energy and increases the chance of a rxn occurring

What biological molecules make up the cell membrane

Phospholipids : acts as main structural fabric and creates a semi permeable barrier. Forms a double layer of water loving phosphate heads on the outside and water fearing fatty acid tails pointing inward

Proteins : transport molecules across the membrane, acts as receptors for cell signaling and provides structural support

Cholesterol: a type of lipid tucked between phospholipid tails, regulates membrane fluidity, keeps membrane stable and flexible

Carbohydrates : sugar chains attached to proteins or lipids on outer surface of cell

How does the structure of phospholipid influence interactions with water and the formation of bilayers?

Since the phospholipid heads are hydrophilic, they create the outer layer to interact with water and regulate what molecules enter the cell. The fatty acid tails are hydrophobic making up the inside layer which is where proteins and transportation happens

Describe difference between saturated fatty acid tail and unsaturated fatty acid tail.

Saturated fatty acid tail will have two equal/similar looking legs, unsaturated fatty acid tails will have one kinked tail looking like a k

Describe different types of membrane proteins and their functions

Transport proteins: move small molecules across membrane

Receptor proteins: binds/receives molecule messages from other cells

Integral protein: can’t be removed from membrane without destroying the membrane, spans across membrane

Peripheral proteins: sits of surface of membrane and can be removed without destroying

Identify 2 functions of cholesterol in the plasma membrane

Regulate fluidity and maintain structural stability

Identify typical structure and functions of eukaryotic plant cells and animal cells

Plant cells have a cell wall, eukaryotic cells do not.

Describe structures and functions of cytoskeleton

Provides structural support, shape, and internal organization

What are catabolic and anabolic rxnx and how do they contribute to cells metabolism

Catabolic: release energy

Anabolic: take in energy

Overall cell metabolism = catabolic + anabolic

Describe ATP and the ATP cycle

ATP: Stores and carries energy around cells

ATP cycle: the process in which living cells use break down and regenerate ATP

Induced fit model

Enzyme changes shape when substrate binds and becomes activated

Explain how enzyme catalyzed rxns are controlled

Enzyme activation: turning on ability for enzyme to carry out rxn (binding of substrate or other activators)

Enzyme inhibition: decrease/stop activity of enzyme (binding of products that block active site, exposure to less optimal environment)

Identify the difference between enzyme catalyzed rxn vs metabolic pathways

Enzyme catalyzed: single chemical step, sped up rxn

Metabolic pathway: sequence of steps working together to form product

Explain how metabolic pathways are controlled in cells

Allosteric binding: binding of molecule to a protein at a site other than the active site

Explain why hydrophilic molecules require transport proteins but hydrophobic molecules do not

Hydrophilic molecules require proteins because they are water loving and polar which inhibits them from passing through the water fearing middle layer

What is membrane fluidity, give examples of things that can change fluidity

Membrane fluidity: how easy it is for molecules in a membrane to move

Factors that can effect fluidity: heat makes molecules move faster making membrane more fluid, chill takes away molecules energy slowing them down making membrane less fluid

Describe difference between passive and active transport

passive: no extra energy is used

Active: cellular energy is consumed

Compare and contrast the two types of diffusion

Simple diffusion: does not need protein to move across a membrane

Facilitated diffusion: solute moves across membrane with help of protein

Identify the two ways water/solutes can move across cell membrane

Passive and active transport

Describe osmosis

Osmosis: net diffusion of water across membrane (water moves from low concentration to high concentration)

Describe active transport

Solute moves from low concentration to high concentration, uses cellular energy, always facilitated

Describe endomembrane system

Exchange material between intracellular structures within a eukaryotic cell

Identify what is meant by membrane permeability

How easy it is for molecules to pass through a membrane

What does it mean for a membrane to be selectively permeable?

Only some molecules have the ability to move across a membrane

When and why do we use tonicity?

Determines the direction and extent of water movement across a cells semi permeable membrane. Used to track water shifts between fluid compartments, prevents cellular damage (cell swelling or shriveling)

Describe advantage of having many membrane bound compartments inside a cell

Prevent conflicting chemical rxns, increase metabolic efficiency, isolate dangerous materials

Compare and contrast role of cell membranes vs cell walls

Membranes: selectively permeable barrier, separate intracellular and extracellular

Walls: extracellular structures, main role is strength and support of cell

Explain how eukaryotic genome differs from prokaryotic genome

Eukaryotic: bigger genome, copying of genomes can occur at many locations at the same time

Prokaryotic: smaller genome, circular shape so copying of genome can only occur in a single cycle starting at point of attachment and continuing throughout the loop

Microfilaments

Made of actin, provide structural support, allows cell to change shape and move

Microtubules

Provide track where vesicles can move through the cell

Intermediate filaments

structural support, holds everything in place