Untitled Flashcards Set

Unit 1

How does the structure result in polarity: oxygen and hydrogen have unequal sharing of electrons resulting in water being labeled as “polar”

How does structure result in adhesion and cohesion through H-bond interactions: water can form H bonds with other water molecules → cohesion, when 2 diff. Molecules form h bonds with each other → adhesion

What chemical characteristics arise from water’s cohesive/adhesive properties: cohesion results in surface tension, adhesion allows water to have a high solvency ability allowing many substance to be dissolved in water, cohesion allows ice to be less dense than liquid water → helpful for organisms when lakes survive, capillary action results from both cohesion and adhesion which is good for plants to bring water up from the soil

Why do living systems require constant input of energy and why do they need to exchange matter with the environment? Law of conservation of energy states that energy cannot be  created nor destroyed. Living systems need energy to grow, reproduce and survive and atoms/molecules are needed from the environment to create new molecules  (carbs, proteins, lipids, and nucleic acids)

What role does carbon, nitrogen, and phosphorus play in building macromolecules? Carbon is necessary for building all macromolecules, N is used for proteins and nucleic acids, and P for nucleic acids and lipids, this is bc carbon is able to bind to other carbons to create a carbon skeleton for other atoms to bond to → cells can make complex molecules

Properties of monomers and what bonds connect monomers of diff. Macromolecules: monomers are chemical subunits to create polymers, polymers are macromolecules, a covalent bond is created between monomers to join together

dehydration synthesis rxns: form covalent bonds, H and OH are removed from monomers so they can join together through the formation of the covalent bond, the H and OH finally join together creating water as a sub product of these rxns

Hydrolysis rxns: cleave covalent bonds, polymers are digested/bonds between monomers are broken, water molecule is also added in order to cleave bonds

Structure and function of nucleic acids according to assembly of their monomers? Nucleic acids are polymers made of monomers of nucleotides, all have 3-carbon sugar, phosphate base, and nitrogenous base, DNA and RNA are nucleic acids differ in type of sugar (deoxyribose vs ribose) and nitrogenous bases (CGAT vs UACG) → diff structure = diff functions

Structure and function of proteins according to assembly of their monomers? Monomers of proteins are amino acids and polymers are polypeptides, directionality with amino group (NH2) at one end and carboxyl (COOH) group at the other,

Structure and function of carbs according to assembly of their monomers? 

Structure and function of lipids according to assembly of their monomers? Nonpolar macromolecules that do not have true monomers but are comprised of fatty acids that can be saturated or unsaturated (double bonds), phospholipids that have a hydrophobic AND hydrophilic region that allows for a dual property

How do R groups determine chemical properties:  central carbon contains the R group which take on hydrophobic, hydrophilic, or ionic characteristic

How do hydrophobic and hydrophilic regions interact: hydrophilic interacts with themselves and water environments while hydrophobic only interacts with themselves and NOT the water environment 

Directionality of nucleic acids and how does it influence S+F: 3’ hydroxyl → 5’ phosphate, DNA is a nucleic acid polymer that is anti-parallel and it runs in the 5’ to 3’ direction, this allows them to be bonded by hydrogen bonds in between adenine and thymine (2 bonds) adn cytosine and guanine (3 pairs)

How does it affect synthesis of nucleic acid polymers: nucleic acids can only be added to the 3’ end, covalent bonds are used to add these nucleic acids

Directionality of proteins: amino acids have directionality with an amino terminus and carboxyl terminus, amino acids are added to the carboxyl end by covalent bonds → linear chain of amino acids creating polypeptide chain, 

Four elements of protein structure: 

1. primary: sequence of amino acids held together by covalent bonds, protein not active here 

2. Secondary: arises through folding of amino acid chains → alpha helix and beta sheets

3. Tertiary: 3d shape of protein, stable, many proteins function at this level, 

4. Quaternary: interactions between multiple polypeptide units, ex: hemoglobin

Directionality of carbs: polysaccharides can be either linear or branched, starch and glycogen are used for energy storage 

Unit 2

Ribosomes reflection of common ancestry in everyday life: all living cells contain a genome and ribosomes reflecting they all share a common ancestor, 

S+F:

1. Ribosomes: synthesize proteins according to mRNA, contained of two sub units that aren’t membrane bound and they are made of rRNA

2. Rough ER: network of membrane tubes, contains ribosomes on it, compartmentalizes the cell, associated with packaging of proteins to ship off to other parts of cell or export out of cell

3. Smooth ER:  network of membrane tubes, no ribosomes, detoxifies the cell and makes lipids

4. Golgi apparatus: flattened sacs in eukaryotic cells, folds and packages proteins to other areas of the cell or out of the cell, 

5. Mitochondria: has a double membrane, outer: smooth, inner: has folds called cristae, creates energy that cell uses for work

6. Lysosomes: membrane bound sacs found in some eukaryotic cells, contains hydrolytic enzymes, these enzymes digest dead/damaged matter or macromolecules, 

7. Vacuole: membrane bound sacs found in some eukaryotic cells, range of roles from storing water and macromolecules to releasing waste from cell

8. Chloroplasts: found in plants, double outer membrane, capture energy from sun and produce sugar through process of photosynthesis

Subcellular components and organelles interactions/contributions to function of cell: 

Structural features of cells that allow them to collect, store, and use energy:

1. Chloroplasts: capture energy from sunlight to produce sugar

• Thylakoid: compartment of chloroplast, organized in stacks called grana, contain chlorophyll pigments that hold photosystems and electron transport chains to carry out light-dependent reactions, folding of these membranes increases efficiency

• Stroma: fluid between inner chloroplast membrane and outside thylakoids, this is where light-independent reactions occur (calvin cycle)

2. Mitochondria: double membraned provides different compartments for different metabolic reactions, capture energy from macromolecules, krebs cycle/light-dependent reactions/citric acid cycle occur in the matrix while electron transport and ATP synthesis are in the inner membrane, folding of inner membrane also increases efficiency

Why are cells small: moving materials like nutrients and waste becomes more difficult the larger a cell in, larger the ratio the better the cell is with moving materials across its surface, as cells increase in volume, the SA decreased making it harder for cells to meet the demand of internal resource and removal of waste → restrict cell size and shape

How is surface area:volume calculated: SA - 6s^2, V - s^3

Structural modifications that allows increased surface area of cells: membrane folding like root hairs allows for more absorption of water in the soil, small intestine has structures like microvilli that increase surface area for absorption of nutrients, 

How does SA:V ratio affect the rate of heat exchange w/ environment: as org. Increase in size, their SA decreases while their V increases, makes it difficult for animals like the elephant to have trouble to release heat, they use their large ears to help with this

How are specialized structures and strategies used for efficient exchange of molecules w/ environment: leaves have stomata that open to obtain molecules and release them from the environment, when open CO2 enters and O2 and water are released, 

Structure of phospholipids and how it maintains internal environment: phospholipids contain both hydrophilic and hydrophobic regions, head is hydrophilic = polar, tail is hydrophobic = nonpolar, tails are in the inside of the bilayer while the heads are exposed to aqueous environments of cell, 

Role of proteins in maintaining internal environment: peripheral proteins are located on the surface of the membrane, hydrophilic, integral proteins span membrane and are hydrophilic and hydrophobic, transmembrane proteins are integral proteins, functions of these proteins are cell-cell transport, enzymatic activity, intercellular joining, transport, signal transduction, and attachment for the ECM 

Structural framework of the fluid mosaic model: shows as a mosaic of proteins in a fluid phospholipid bilayer, held tg by hydrophobic reactions which are weaker than covalent bonds, allow lipids and proteins to shift across the membrane, contains cholesterol (steroid) and this helps regulate bilayer fluidity, certain carbs function as cell markers (glycoproteins and glycolipids) 

Molecules that pass through membrane: small, nonpolar molecules, nitrogen, oxygen, carbon dioxide

Substances that pass through transport proteins and embedded channels: hydrophilic substances that are large and polar pass through transport proteins that are tunnels spanning the membrane or through carrier proteins that change shape to move a substance across the membrane

Molecules that pass through in small amounts: small polar molecules like water

Type of boundaries of cell walls: structural - maintains shape of cell, prevents cell rupture when internal environment has high levels of water, helps plants stand up against gravity (transpiration), permeable - plasmodesmata allows transfer of nutrients, waste and ions

Type of molecules cell walls are made of: complex carbs, plants are made of cellulose, fungi - chitin, prokaryotes - peptidoglycan, a polymer with sugars and amino acids

Passive transport: net movement of molecules from high concentration to low concentration, no metabolic energy needed

1. Diffusion: movement of molecules from high to low directly across membrane, small nonpolar molecules, nitrogen, oxygen, CO2

2. facilitated diffusion: movement of molecules from high to low concentration, done through transport proteins, allows hydrophilic molecules and ions to pass

Active transport: cell needs to move molecules against the concentration gradient, uses ATP in order to do so

How do concentration gradients form across membranes: occurs when a solute is more concentrated in one area than another, a membrane separates the two groups creating this gradient

How do large molecules move in/out of cell:

1. Endocytosis: cell uses energy to take in macromolecules and creates new vesicles from the membrane 

• Phagocytosis: cell takes in large particle

• Pinocytosis: cell take sin ECM fluid containing dissolved substances

• Receptor-mediated endocytosis: receptor proteins on cell are used to capture specific molecules to take into the cell

2. Exocytosis: used to remove large particles from cell, internal vesicles fuse with membrane and secrete the macromolecules from cell, hormones and waste are examples that would be removed

Large quantities of water across membrane: pass through aquaporins in facilitated diffusion

Polarization of membrane: through movement of ions which help in formation of gradients like membrane potential: electrical potential difference across the membrane, 

What molecules are needed for active transport to occur: rely on carrier proteins called pumps, ATP, and AT maintain and establish the concentration gradient,

• Cotransport: secondary active transport that uses energy from electrochemical gradient to transport 2 different ions across the membrane

1. Symport: 2 ions transported in same direction

2. Antiport: 2 ions transported in 2 different directions

How does Na+/K+/ATPase contribute to membrane potential: sodium channels open up, sodium ions diffuse, then potassium channels open, and potassium diffuses out, the pump maintains the potential, takes 3 sodium and pumps them against the [], and pumps 2 potassium ions the other directions 

Ways to describe tonicity of environment: osmolarity: total solute concentration in solution, water has high solvency abilities, tonicity: measure of [] of solute in two solutions, internal cellular environments can by hypotonic (less solute, more solvent), hypertonic (more solute, less solvent), or isotonic (= [] of solute and solvent), 

Diff. in osmolarity effect on movement of water: water moves by osmosis into area with higher solute concentration, water [] and solute [] are inversely related, when isotonic there’s no net movement of water

How does constant movement of particles through membrane affect homeostasis: osmoregulation maintains the equilibrium, cell wall helps maintain it during environment hypotonicity → turgor pressure

Osmoregulation: maintains water balance, allows organism to maintain their internal solute concentration

Water potential: measures tendency of water movement by osmosis, calculated from pressure and solute potential, moves from high WP to low WP, more (-) a calculation is, the more likely the water will move into that area, WP of pure water in open container = 0

Solute potential: -iCRT, i = ionization constant (sucrose = 1, NaCl = 2), C = molar [], R = 0.0831/pressure constant, T = temp. In kelvin

How do organisms maintain water balance: osmoregulation, increasing amount of solute in water increases SP but decreases WP, 

Membrane-bound organelles that help with compartmentalization: eukaryotic cells have additional internal membranes that allow for better compartmentalization, allow for various metabolic processes to occur simultaneously to increase efficiency

Internal membranes when facilitating cellular processes: this minimizes competing interferences, ex: hydrolytic enzymes function in acidic environments and through compartmentalization, this is able to happen while the rest of the cytoplasm is at a more neutral environment, 

similarities/differences in compartmentalization of prokaryotic and eukaryotic cells: both have a plasma membrane, eukaryotic cells have more internal membrane-bound organelles compared to prokaryotic cells, ex: genetic information is found in the nucleus instead of the nucleic region

Mitochondria and chloroplasts evolution: mitochondria and chloroplasts evolved from free-living prokaryotes via endosymbiosis: anaerobic prokaryotic cell was engulfed by cell and this became mutually beneficial, cell provided protection, and the prokaryotic cell provided energy, supported by evidence of similar structures like double membranes, each have their own circular DNA and can reproduce themselves, contain own ribosomes as well