BIO 102 Lecture Notes - Lecture 6: Anoxygenic Photosynthesis, Huronian Glaciation, Chloroplast

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10 Oct 2016

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Cells require energy: cell are constantly using energy to maintain organization. Two ways to store energy in cell: chemical bonds, gradients across membranes. Energy in the cell provided by atp. Atp: directly used to power enzymes but not safe to store in large quantities. Carbohydrates and lipids: contain lots of energy in their bonds but not directly used to power enzymes. Biological membranes: all cells are bounded by semi-permeable membranes. Ionic or polar substances cannot difuse through the membrane but are allowed through by membrane proteins. A concentration gradient where one side of a membrane has a high concentration of a molecule is one of the ways a cell can store or convert energy. Energy transfer: atp is made by atp synthase a membrane localized, uses a h+ gradient to synthesize. All organisms in the tree of life make atp. Energy source and electrons electron transport hydrogen ion gradient (across membrane) atp synthase (membrane) atp.

Related Questions

Question 1

Plasma membranes are selectively permeable. This means that

	A.	glucose cannot enter the cell.
	B.	the plasma membrane allows some substances to enter or leave a cell more easily than others.
	C.	plasma membranes must be very thick.

Question 2

Oxygen molecules O₂ crosse a plasma membrane by

	A.	passive transport
	B.	osmosis
	C.	active transport

Question 3

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.

		A. energy and channel proteins; against (up)
		B. transport proteins that make channels ; down
		C. energy ; down

Question 4

When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will

		A. move to the side with lower water concentration
	B.	move to the side with higher water concentration
	C.	move to the side with lower solute concentration

Question 5

Kinetic energy differs from chemical energy in that

	A.	chemical energy is a particular form of kinetic energy.
	B.	kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
	C.	kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement.

Question 6

When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction.

	A.	exergonic; endergonic
	B.	endergonic; exergonic
	C.	spontaneous; exergonic

Question 7

When an enzyme catalyzes a reaction

		A. it raises the activation energy of the reaction.
		B. it lowers the activation energy of the reaction.
		C. it is used once and discarded.

Question 8

Which of the following statements regarding enzyme function is false?

		A. An enzyme's function depends on its three-dimensional shape.
		B. Enzymes are very specific for their substrates.
		C. Enzymes are used up when they catalyze a chemical reaction so must be synthesized for each new chemical reaction

Oxidation reduction reactions are coupled and referred to as redox reactions. Electrons are the atomic particles that participate in chemical bonds and are used by cells to generate an electrochemical gradient across membranes. Cells have require ATP to maintain membrane properties and metabolism, because ATP has high energy phosphate bonds that may be cleaved to release energy. Cells synthesize ATP through phosphorylation. Cells must perform many chemical reactions within a certain temperature, pH and osmolarity range. In general chemical reactions in a cell would occur over time without enzymes, and it might require big changes in temperature. Enzymes are organic catalysts that increase the rate of reactions without being altered in the process. Review protein structure and function in chapter 2 to understand how enzymes work. Enzymes also may act as 'switches' and be the rate controlling steps in a biochemcial pathway. There are several ways enzyme activity is altered by other factors or physical conditions.

1. The bacterial enzyme streptokinase is used to digest fibrin in patients with atherosclerosis. Why doesn't the injection of streptokinase cause a streptococcal infection?

2. How do we know that streptokinase will break down fibrin and not functional tissue?

3. 5 bromouracil is used as an anti cancer drug it is mistaken for thymine by cellular enzymes during DNA replication, name the enzyme site the nucleoside analog is probably binding.

Most of a cell's energy is derived from the oxidation of carbohydrates. Glucose is the most common oxidized carbohydrate. There are two types of glucose catabolism respiration and fermentation.

4. Is glucose completely broken down in respiration or fermentation?

greenhedgehog909

15. While texting on your phone, the central nervous system directs your fingers by sending commands that are carried by_________________.

		efferent neurons.
		afferent neurons.
		glial cells.
		schwann cells.
		None of the above

13. Energy can be harvested from the glucose molecule and generate ATP ONLY IF: (Select all that apply)

		mitochondria are present within the cell
		the cell has membrane proteins that can pump hydrogen ions (i.e., H⁺)
		oxygen can accept electrons
		the cell has enzymes that can catalyze reactions in glycolysis (i.e., PFK)
		the cell can carry oxidation-reduction reactions

12. Marathon runners tend to do what is called "carbo loading" (that is, eat a lot of pasta) before their big race. Carbohydrates are source of energy because provide glucose to the cells. Why "carbo loading" is beneficial to the marathon runner?

		The bonds in the carbohydrate/glucose have high potential energy
		Through the process of anabolism the runner will break down the carbohydrate/glucose
		The bonds in the carbohydrate/glucose have low potential energy making easily to chew
		Makes the runner feel full for a longer period of time

9. Energy supports _____________________ to maintain homeostasis, which results in the well-being of the organism.

pucemarten302

BIO 102 Lecture Notes - Lecture 6: Anoxygenic Photosynthesis, Huronian Glaciation, Chloroplast

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