Ap BIO midterm

Is water polar, nonpolar, or neutral?

Polar!

______ creates properties that support life

hydrogen bonds

High specific heat

How much energy it takes to raise 1g of a substance by 1 degrees celsius-- it takes a lot of energy to raise the temperature of water!

High heat of vaporization

It takes a high amount of energy to turn water into vapor!

Cohesion

Water sticking with water

Adhestion

Water sticking with a different molecule

Surface tension

a liquid's surface that resists external force due to cohesive forces

temperature regulation

when water evaporates, the heat molecules leave faster, leaving the cold molecules-- which cools

What is the more electronegative charge in H2O?

O!

Where do electrons go towards in the H2O molecule?

O, because of it's more negative charge it causes an unequal sharing of electrons!

Is hydrogen partially positive or negative?

Positive! That's what causes O to form hydrogen bonds with it.

What type of bonds do water molecules have

polar covalent bonds / HYDROGEN bonds

name three biological function of water

temperature regulation, water transport, allowing insects like water striders to walk on water

what are the three elements in ALL macromolecules?

Carbon, Hydrogen, Oxygen

what are the four macromolecules?

carbohydrates, lipids, proteins, nucleic acids

Carbohydrates

C, H, O; Energy + structure

Lipids

C, H, O; Hydrophobic; energy storage, membranes

Proteins

C, H, O, N, S; Enzymes, structure, transport

Nucleic Acids

C, H, O, N, P; genetic information

Polymer

molecules that are made up from monomers

Monomer

the building blocks of polymers

What is dehydration synthesis?

A chemical reaction that removes OH and H from two monomers to create a covalent bond between them.

What is produced as a byproduct of dehydration synthesis?

Water (H2O)

What is hydrolysis?

Hydrolysis is a chemical reaction that adds OH and H to two monomers to break covalent bonds between them.

What type of bonds do carbs have?

Glycosidic

What type of bonds do proteins have?

Peptide

What type of bonds do nucleic acids have?

Phosphodiester

name three monomers of carbohydrates

glucose, fructose, galactose

what do glucose, fructose, and galactose have in common?

6 carbons, 12 hydrogen, 6 oxygens.

what type of saccharide is glucose, fructose, and galactose?

monosaccharide

what is a polysaccharide?

when three or more monosaccharides are joined together

what do ALL living organisms use for fuel

glucose

what turns glucose into ATP?

the mitochondria

what does glucose break down into to become ATP?

co2 + h2o

What is the 2 main polysaccharides for plants?

starch, and cellulose

what does starch do?

stores energy

when we eat starch, what happens?

our enzymes break starch down into glucose to be used for energy

what type of glucose is starch

alpha glucose

what does cellulose do?

keeps plants rigid by structuring the cell wall

what happens when we eat cellulose?

we cannot hydrolyze cellulose, so it's not a good source of energy

give an example of who can hydrolyze cellulose

cows use bacteria to hydrolyze cellulose in grass into energy

what type of glucose is cellulose

beta glucose

what polysaccharide do animals use

glycogen

what can animals convert carbs from

lipids

why can we convert carbs between lipids

both are made of C, H, and O

give a real example of how we use glucose

by excessing, our body hydrolyzes stored glucose in order to create ATP for energy to use for exercising

Isotope

Atom with same element, different neutrons.

Radioactive isotope

Isotope whose nucleus decays, emitting radiation.

Iodine-131

Used in medical imaging for thyroid diagnosis.

Carbon-14

Used for radiocarbon dating of fossils.

Covalent bond

Electrons shared between atoms, e.g., water H₂O.

Ionic bond

Electrons transferred, forming charged ions, e.g., NaCl.

Hydrogen bond

Weak attraction involving hydrogen and electronegative atom.

Van der Waals forces

Weak interactions from transient dipoles in molecules.

Cohesion

Water molecules stick together, aiding capillary action.

Adhesion

Water molecules stick to other substances, aiding transport.

High specific heat

Water resists temperature changes, stabilizing environments.

High heat of vaporization

Water absorbs heat before evaporating, cooling surfaces.

Universal solvent

Water dissolves many polar and ionic substances.

Lower density of ice

Ice floats, insulating aquatic life in cold weather.

Functional group

Group of atoms determining molecule's chemical properties.

Carbon versatility

Four valence electrons enable diverse bonding configurations.

Carbohydrates

Provide energy and structural support, e.g., glucose.

Proteins

Perform functions like catalysis and transport, e.g., hemoglobin.

Lipids

Store energy and form membranes, e.g., triglycerides.

Nucleic acids

Store and transmit genetic information, e.g., DNA.

Monosaccharides

Monomers of carbohydrates, e.g., glucose.

Amino acids

Monomers of proteins, linked by peptide bonds.

Fatty acids

Monomers of lipids, joined by ester bonds.

Nucleotides

Monomers of nucleic acids, e.g., adenine.

Nucleotides

Building blocks of nucleic acids linked by phosphodiester bonds.

Phosphodiester bonds

Link nucleotides via sugar and phosphate groups.

Dehydration synthesis

Links monomers, releasing water during polymer formation.

Hydrolysis

Breaks polymers into monomers by adding water.

Amino acid sequence

Single changes can alter protein structure and function.

Sickle-cell hemoglobin

Example of disease caused by amino acid sequence change.

DNA structure

Double-stranded helix with deoxyribose sugar and A, T, C, G.

RNA structure

Single-stranded with ribose sugar and A, U, C, G.

Prokaryotic cells

Lack membrane-bound organelles, have circular DNA.

Eukaryotic cells

Contain membrane-bound organelles and linear DNA.

Nucleus

Stores genetic information and controls cell function.

Mitochondria

Powerhouse of the cell, produces ATP.

Chloroplasts

Organelles for photosynthesis in plant cells.

Ribosomes

Sites of protein synthesis within the cell.

Endoplasmic reticulum (ER)

Rough ER synthesizes proteins; Smooth ER synthesizes lipids.

Golgi apparatus

Modifies, sorts, and packages proteins for transport.

Surface area-to-volume ratio

Smaller cells exchange materials more efficiently.

Phospholipids

Form bilayer structure of cell membranes.

Fluid Mosaic Model

Describes membrane fluidity and protein diversity.

Selective permeability

Membranes allow specific molecules to pass through.

Cell wall

Provides structure and rigidity to plant cells.

Osmoregulation

Maintains solute and water balance in organisms.

Hypotonic solution

Causes cells to swell due to water influx.

Hypertonic solution

Causes cells to shrink as water exits.

Isotonic solution

No change in cell size occurs.

Endocytosis

Process of transporting large particles into the cell.

Exocytosis

Process of transporting large particles out of the cell.

Molecule permeability

Nonpolar small molecules pass freely through membranes.

Concentration Gradient

Difference in concentration of molecules across a membrane.

Diffusion

Movement of molecules from high to low concentration.