AP Bio Unit 2 Review

Ribosomes

Made up of DNA and proteins, synthesizes proteins

Rough ER

Has ribosomes attached to membrane, packages newly made proteins to be exported out the cell

Smooth ER

Does not have ribosomes, detoxifies and creates lipids

Golgi Apparatus

Receives proteins from ER and processes proteins

Lysosomes

Only found in animal cells, contains digestive enzymes which break down and digest old or damaged cell parts

Vacuoles

Stores water and releases waste from cell

Chloroplasts

Captures energy from the sun and produces sugar for organism

Thylakoid

Site of light dependent reactions in chloroplast

Stroma

Fluid between inner chloroplast membrane and outside thylakoids, carbon fixation occurs here

Mitochondria

Site of ATP production

Which cells have a more efficient exchange of materials with the environment, small or large cells?

Small

What happens as a cell decreases in volume?

The relative surface area decreases

What happens when organisms increase in size?

The surface area-to-volume ratio decreases

What is the purpose of stroma in plants?

Allows plants to let certain things enter and leave the cell through tiny pores

What part of the phosphate is hydrophilic?

Phosphate head

What part of the phosphate is hydrophobic?

Fatty acid tail

What are the functions of membrane proteins?

Transport, cell-to-cell recognition, enzymatic activity, signal transduction, intercellular joining, attachment for cytoskeleton

What holds the cell membrane together?

Hydrophobic interactions

What does cholesterol do in the cell membrane?

Regulates fluidity under different environmental conditions

What do carbohydrates do in the cell membrane?

Serves as cell markers

What is a glycoprotein?

One or more carbohydrates attached to a membrane protein

What is a glycolipid?

Lipid with one or more carbohydrate attached

What happens in a hypertonic solution?

Cell loses water and shrinks

What happens in an isotonic solution?

Equal concentration on both sides

What happens in a hypotonic solution?

Cell gains water and increases in size

What two types of cells want hypotonic solutions?

Plant cells and bacteria

What is the purpose of osmotic solutions?

To spread out molecules

What molecules can pass through the cell membrane without the use of proteins?

Small nonpolar molecules (N2, O2, CO2)

What is a channel protein?

A hydrophilic tunnel spanning the membrane that allows specific target molecules to pass through

What is a carrier protein?

Tunnel that spans the membrane that changes shape to move a target molecule from one side of the membrane to the other

What is a concentration gradient?

When a solute is more concentrated in one area than another

What is passive transport?

Movement of molecules from a high concentration to a low concentration WITHOUT using energy

What are the two different types of passive transport?

Diffusion and facilitated diffusion

What is diffusion?

Movement of molecules from high concentration to low concentration

What is facilitated diffusion?

Movement of molecules from high concentration to low concentration through transport proteins

What is active transport?

Requires direct energy to move molecules from low concentrations to high concentrations

What is endocytosis?

When a cell uses energy to take in macromolecules and particulate matter by forming new vesicles from the plasma membrane

What are the three types of endocytosis?

Phagocytosis, pinocytosis, receptor-mediated endocytosis

Phagocytosis

When cells take in large particles

Pinocytosis

When cells take in extracellular fluid containing dissolved substances

Receptor-Mediated Endocytosis

Receptor proteins on the cell membrane are used to capture specific target molecules

Exocytosis

Internal vesicles use energy to fuse with plasma membrane and secrete large macromolecules out of cell

Cotransport

Secondary active transport that uses energy from an electrochemical gradient to transport two different ions across the membrane through a protein

What are the two types of cotransport?

Symport and antiport

Polarization of cell membrane can be caused by?

Movement of ions

Cell membrane allows?

Formation of gradients

Sodium Potassium pump is an example of what kind of transport?

Active

What does Sodium Potassium Pump pump?

3 Na+ & 2 K+

Symport

Two different ions are transported in the same direction

Antiport

Two different ions are transported in opposite directions

What does folding of inner membranes do?

Increases surface area and allows for more ATP to be made in mitochondria, allows for higher efficiency of light dependent reactions in chloroplasts

Osmosis

Diffusion of free water across a selectively permeable membrane

Osmolarity

Total solute concentration in a solution

Tonicity

Measurement of relative concentrations of solute between two solutions

Solute and solvent relationship in hypertonic?

More solute and less solvent

Solute and solvent relationship in hypotonic?

Less solute and more solvent

Water moves by osmosis to an area with a _________ solute concentration.

Higher

Solutes diffuse from ____________ to _________________.

Hypertonic, hypotonic

Turgor pressure

When cell wall expands and exerts pressure on the cell

Water potential

Measures tendency of water to move by osmosis

Water moves from an area of ________ water potential to an area of ________ water potential.

High, low

What does it mean when the water potential is more negative?

Water will most likely move into the area

What is the water potential of pure water in an open container?

0

What does increasing the amount of solute in water mean?

An increase in solute potential and a decrease in water potential

What does increasing water potential do?

Increases pressure potential

What does decreasing pressure potential do?

Decreases water potential

Endosymbiosis

A free living aerobic prokaryote was engulfed by an anaerobic cell

How did chloroplasts and mitochondria form in prokaryotes and eukaryotes?

By endosymbiosis, to which they eventually lost their individual functions and instead became a part of the new cell