Chapter 3 - Cell Structure and Function
What structure surrounds all cells and acts as a boundary and gatekeeper?
Plasma Membrane
What two major types of molecules primarily make up the plasma membrane?
Proteins & Phospholipids
What term describes the relative amount of disorganization in a system?
Entropy
What molecule is broken down during cellular respiration to release energy used to make ATP?
Glucose
What pigment is primarily responsible for capturing light energy during photosynthesis?
Chlorophyll
What is the semifluid medium inside a cell that contains water, salts, and dissolved organic molecules?
Cytoplasm
Why can glucose not easily diffuse directly through the phospholipid bilayer?
Because it is a large and polar molecule
What is the term for the sum of all chemical reactions in a cell?
Metabolism
What stage of cellular respiration occurs in the cytoplasm and does not require oxygen?
Glycolysis
What is the equation for Photosynthesis
What type of microscope is used to study the detailed external surface of a cell?
Scanning electron microscope
What protein helps glucose cross the plasma membrane through facilitated diffusion?
GLUT4 carrier protein
What is the difference between catabolism and anabolism?
Catabolism: breaks molecules down
Anabolism: builds molecules up
What are the major products of the Citric Acid Cycle (Krebs Cycle) from one glucose molecule?
4 CO2, 6 NADH, 2 FADH2, 2 ATP
Why do leaves appear green?
Green wavelengths are reflected by the chlorophyll
What is the difference between magnification and resolution?
Magnification: increases image size
Resolution: the ability to distinguish two nearby objects as separate.
What type of transport uses a carrier protein but does not require energy because molecules move down their concentration gradient?
Facilitated diffusion
How do exergonic and endergonic reactions differ in terms of energy?
Exergonic reactions release energy
Endergonic reactions require an input of energy
Why does the Citric Acid Cycle turn twice for every glucose molecule?
One glucose produces two pyruvate, which results in two molecules entering the cycle.
Where do the light-dependent reactions occur, and what two energy-containing molecules do they produce?
Thylakoid
ATP & NADPH
State the three parts of cell theory.
1. All organisms are made of one or more cells
2. Cells are the basic unit of structure/function
3. All cells come from other cells.
A molecule is being moved from an area of low concentration to high concentration using ATP and a carrier protein. What type of transport is occurring, and why is ATP required?
Active transport
ATP is needed because the molecule is moving against its concentration gradient.
According to the laws of thermodynamics, why do living cells require a constant input of energy even though energy cannot be created or destroyed?
Every energy transformation loses some usable energy as heat, so cells need a continual energy input to maintain their homeostasis and processes
Explain how a H+ proton gradient results in ATP production during chemiosmosis.
H⁺ accumulates in the intermembrane space and flows back into the matrix through ATP synthase, producing ATP
What are the two products of photosynthesis, and which reactant is the source of the oxygen released?
Glucose and oxygen
The released oxygen comes from the splitting of water.