AP Biology Unit 2 Study guide

1. Researchers are studying bacteria that normally live in high salinity environments to investigate how they can survive these harsh conditions. What mechanism would they be most likely to observe in these bacteria?

A cell wall to aid in reducing osmosis from the cells to the environment

1. Mitochondria are found in most eukaryotic cells and contain their own DNA and ribosomes that are similar to those typical of many prokaryotic cells. What justifies these observations?

An ancestral cell most likely engulfed a prokaryotic cell in a relationship that proved beneficial for both cells.

What would likely move through the lipid bilayer of a plasma membrane rapidly?

CO2

What characteristics are in both prokaryotic and eukaryotic cells?

Cell membrane, ribosomes, DNA, RNA

What strategy have animals developed to stabilize their cell membrane?

Cholesterol between phospholipids

Movement of substances into and out of a cell is dependent on the size, charge, and concentration gradient of the substance across the plasma membrane. What represents active transport into a cell?

Diffusion of potassium ions across a neuron membrane against its concentration gradient, through the use of ATP.

What best describes an advantage that eukaryote organisms have over prokaryote organisms?

Eukaryotes have organelles that allow for compartmentalization of cellular processes, which increases the efficiency of those processes.

The small intestines are the main site of nutrient and water reabsorption. This can be accomplished because of the villi and microvilli folding into tiny hair-like projections. These projections aid in absorption by

Increasing surface area of the small intestines

What is the direction of the net flow of water?

Osmosis - the direction of increased solute concentrations moving to lower concentrations.

5. Cells contain smaller components called organelles that are necessary for a cell's survival. Organelle functions have often been compared to components of larger systems. What functional difference between the rough and smooth endoplasmic reticulum is explained by the structural differences between them?

Rough can synthesize and package proteins for export, and smooth cannot package proteins.

A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water (which has nothing dissolved in it)-equal to the volume of blood lost-is transferred directly into one of his veins. Normal blood has a small amount of salt in it. What will be the most probable result of this transfusion

The patient's red blood cells will shrivel up because the blood fluid has become hypertonic compared to the cells.

Using surface area and volume, why is it advantageous for cells to be smaller

Volume increases faster than surface area and cells need to move nutrients and waste in efficiently.

What is Ψ?

Water potential

How do you find solute potential?

iCRT Where i = Ionization constant C = Molar concentration R = Pressure constant (0.0831) T = Temperature °K (273 + °C of solution)

Which types of molecules are the major structural components of the cell membrane?

phospholipids and proteins