Bio review :(

What is the composition of water molecules?

Made up of 1 Oxygen atom and 2 Hydrogen atoms.

What kind of charge does water have?

polar and has partial positive and negative charges.

What type of bonds can polar molecules form?

They can form hydrogen bonds (hydrophilic).

What characterizes hydrophobic molecules?

lack partial charges and cannot form hydrogen bonds.

What is an exception to the rule of polar molecules?

Carbon dioxide is non-polar and hydrophobic.

What is a hydrogen bond?

A weak attraction compared to covalent bonds forming from attraction between electrical charges.

How are hydrogen bonds characterized?

They are easy to break and involve a hydrogen partial positive charge.

What are macromolecules?

Large molecules such as carbohydrates, proteins, and nucleic acids.

What do acids do in a solution?

release H+ protons and lower the pH.

What do bases do in a solution?

accept H+ protons and increase the pH.

What structures surround all living cells?

Cell membranes protect and contain organelles.

What defines life according to scientists?

metabolism (taking in and processing resources) and reproduction (producing offspring with those resources).

What makes up the basic structure of a cell membrane?

Phospholipid bilayer with hydrophilic heads and hydrophobic tails.

What are amphipathic molecules?

Molecules that have both hydrophilic and hydrophobic parts.

How does temperature affect diffusion?

faster at higher temperatures.

What is the definition of diffusion?

Spontaneous movement of molecules from areas of high concentration to low concentration.

What is passive transport?

Movement of molecules that doesn’t require energy, occurring down a concentration gradient.

What is facilitated diffusion?

Transport of molecules through a membrane protein when substances are too large or polar.

What is active transport?

Energy is used to move substances from low to high concentration across a membrane.

What is osmosis?

Water flows through a semi-permeable membrane from low solute to high solute concentrations.

What distinguishes a hypotonic solution?

Lower concentration of dissolved substances compared to the inside of the cell.

What is a hypertonic solution?

Higher concentration of dissolved substances compared to the inside of the cell.

What is selective permeability?

Some substances can pass through the membrane barrier more readily than others.

What are transmembrane proteins?

Proteins that function as tunnels and allow ions and other small molecules to pass.

What role do pumps play in transport?

They help transport substances against the concentration gradient using energy from ATP.

What is ATP?

Adenosine triphosphate, an energy-carrying molecule in cells.

How do channels in the membrane function?

They facilitate the diffusion of specific ions or molecules across the lipid bilayer by an open channel

How do carriers in the membrane function

bind to specific substances and undergo conformational changes to transport them across the membrane.

what do peripheral membrane do and where are they located

proteins located on the outer or inner surface of the membrane that help with signaling and maintaining the cell's shape.

what are transmembrane proteins and where are they located

span across the lipid bilayer, with portions exposed to both the extracellular and intracellular environments, playing critical roles in transport and communication.

Carbohydrates

project from the bilayer and act as “street addresses” to identify individual cells are present in the extracellular portion of the cell membrane

Saturated phospholipids

the fatty acid tails straight ridged making it less fluid

Unsaturated phospholipids

have kinked fatty acid tails, resulting in a more fluid membrane structure and not ridged

what molecule has the hardest time passing through the membrane

Charged Ions (Na+ K+ Cl+)

what molecule has the easiest time passing through the membrane

Small nonpolar molecules (O2,Co2,N2) 

Transmembrane protein

function as tunnels and allow ions and other small molecules pass does; don’t form an open channel for molecules to flow through 

Will phospholipids tails become more or less fluid in warmer temperatures

more fluid

R-groups

inside of the protein there are R-groups that have sizes and charges that allow specific ions to pass but others not to located in both channels and carriers