Unit 2 Level 75 Review

Polarity of Water?

Water is a polar molecule

Cause of Water Polarity

Water is a polar molecule because it has a partial positive charge on one end (hydrogen) and a partial negative charge on the other end (oxygen).

Interact or Not: Water

Water molecules interact with one another

How does water molecules interact?

Water molecules interact through hydrogen bonding, where the partially positive hydrogen of one water molecule is attracted to the partially negative oxygen of another water molecule.

Emergent property of water

Cohesion

Cohesion Info

The property of water that allows water molecules to stick to each other, forming hydrogen bonds and creating surface tension.

Emergent property of water (2)

Adhesion

Adhesion Info

The property of water that allows it to stick to other substances, such as when water sticks to the walls of a plant's xylem vessels.

Emergent property of water (3)

High specific heat

High Specific Heat Info

Water has a high specific heat, meaning it can absorb and store a large amount of heat energy without a significant change in temperature.

Emergent property of water (4)

Neutrality

Water Neutrality

Neither Acidic or Basic

Emergent property of water (5)

Low Density as Solid

Density of Water Info

Water expands when it freezes, which is unusual for most substances. This expansion creates less dense ice, allowing it to float on water bodies.

Emergent property of water (6)

Versatility as a solvent

Versatility as Solvent Info

Water is a versatile solvent, meaning it can dissolve a wide range of solutes due to its polarity and ability to form hydrogen bonds.

Endothermic reaction

Is a chemical reaction that absorbs heat energy from its surroundings, resulting in a decrease in temperature. (Anabolic)

Exothermic reaction

Is a chemical reaction that releases heat energy to its surroundings, resulting in an increase in temperature. (Catabolic)

Anabolic reaction

Is a metabolic reaction that builds larger molecules from smaller molecules, requiring energy input.

Catabolic reaction

Is a metabolic reaction that breaks down larger molecules into smaller molecules, releasing energy.

Energy vs. time curves for anabolic and catabolic reactions

Anabolic reactions have energy vs. time curves that show an increase in energy as the reaction progresses, while catabolic reactions have energy vs. time curves that show a decrease in energy.

Activation energy

The minimum amount of energy required for a chemical reaction to occur.

Catalyst

Is a substance that increases the rate of a chemical reaction by lowering the activation energy, without being consumed in the process.

Enzyme

Is a biological catalyst, usually a protein, that speeds up specific chemical reactions in living organisms.

Lock-and-key (induced fit) model

Describes how enzymes bind to their specific substrates, where the enzyme's active site (lock) undergoes a conformational change to fit the substrate (key) and facilitate the reaction.

Denaturation

Is the process in which proteins lose their structure and function due to extreme conditions such as high temperature or pH.

Dehydration synthesis

Is a chemical reaction that links monomers together by removing a water molecule, forming a covalent bond and creating a larger polymer.

Hydrolysis

Is a chemical reaction that breaks down polymers into monomers by adding a water molecule, breaking the covalent bond.

ATP

Is a high-energy molecule used by cells to store and release energy during cellular processes.

Phospholipid

A molecule composed of a hydrophilic head (phosphate group) and hydrophobic tails (fatty acid chains), forming the main component of cell membranes.

Hydrophobic

Repel or do not mix with water due to their nonpolar nature.

Hydrophilic

Are attracted to or mix well with water due to their polar nature.

Bilayer

Refers to the arrangement of phospholipids in a cell membrane, where two layers of phospholipids align with their hydrophobic tails facing inward and their hydrophilic heads facing outward.

Passive transport

Is the movement of substances across a cell membrane without the use of energy, driven by concentration gradients.

Simple diffusion

Is the passive movement of molecules from an area of higher concentration to an area of lower concentration, down their concentration gradient.

Facilitated diffusion

Is the passive movement of molecules across a cell membrane with the help of transport proteins, down their concentration gradient.

Osmosis

Is the passive movement of water molecules across a selectively permeable membrane, from an area of lower solute concentration to an area of higher solute concentration.

Active transport

Is the movement of substances across a cell membrane against their concentration gradient, requiring the use of energy (usually ATP).

Pumps

Are membrane proteins involved in active transport, using ATP to move ions or molecules across the cell membrane against their concentration gradient.

Endocytosis

Is the process by which cells engulf external substances by forming a vesicle from the cell membrane and bringing the substances inside the cell.

Exocytosis

Is the process by which cells release internal substances by fusing a vesicle containing the substances with the cell membrane and expelling the contents outside the cell.

Carbohydrate (Functions)

Functions: Energy storage, structure (especially plants), cell communication

Protein (Functions)

Structure, movement, enzymes, transport,
some hormones, immune system, receptors

Lipid (Functions)

Functions: Energy storage, insulation/padding, hormones, cell membranes (phospholipids)

Nucleic Acid (Functions)

Function: Store and transmit genetic information

Protein (Structure)

Structure: Chains of amino acids
- Joined by peptide bonds  Dipeptide  Polypeptide
(Monomers  Dimers  Polymers)

Carb (Structure)

monosaccharide disaccharide polysaccharide

Lipids (Structure)

Triglycerides, Steroids

Nucleic Acid (Structure)

Structure: Phosphate and 5-C sugar (backbone); nitrogenous base
(A, T, C, and G)

How to know if something is water soluble?

It has to be polar (Contains N or O)

Lipid (monomers)

glycerol and fatty acids

Lipid (polymers)

diglycerides and triglyceride

Protein (polymers)

polypeptides

Protein (monomers)

amino acids

Carbohydrates (polymers)

polysaccharides and disaccharides

Carbohydrates (monomers)

monosaccharides

Nucleic Acids (polymers)

DNA and RNA

Nucleic Acids (monomers)

nucleotides

Carrier proteins

bind the specific solute to be transported and undergo a series of conformational changes to transfer the bound solute across the membrane

Channel Proteins

interact with the solute to be transported much more weakly

Glycolipid

Help with cell recognition

Glycoprotein

Help as receptors for chemical signals