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Explain cell theory

Unit 2 Exam 2 Study Guide

Explain cell theory

Below is a sampling of questions that you may find on this exam. If you can completely and accurately answer the following questions, you should have a solid working understanding of all the material and concepts we have covered in this unit. You will also find the competencies and learning objectives that you have been working with so far in this course.

You may also want to go back to the practice quizzes, project(s), worksheets, and textbook chapters from this unit to help you study the concepts related to the competencies and objectives.

Unit 2 Competencies and Learning Objectives

Competency 4: Recognize the cellular basis of life

Learning Objective 4.1: Explain cell theory

Learning Objective 4.2: Identify the structure and function of cellular components

Learning Objective 4.3: Differentiate between prokaryotic and eukaryotic cells

Learning Objective 4.4: Explain why cells are small

Learning Objective 4.5: Compare viruses to cells
Learning Objective 4.6: Identify the components of the cell membrane
Learning Objective 4.7: Explain the different forms of cell transport
Learning Objective 4.8: Explain the evolutionary origin of mitochondria and chloroplasts (endosymbiosis)

Competency 5: Describe the lifecycle of the cell, its regulation, and its role in growth, development, and reproduction

Learning Objective 5.1: Identify the events of the cell cycle

Learning Objective 5.2: Explain how sexual life cycles are used by various organisms

Learning Objective 5.3: List the process and major events of mitosis and meiosis

Learning Objective 5.4: Identify the three sources of genetic variation

Learning Objective 5.5 Describe the function of apoptosis in development and in the prevention of cancer

Learning Objective 5.6: Differentiate between mitosis and meiosis

Learning Objective 5.7: Differentiate between sexual and asexual reproduction

Competency 6: Recognize the role of energy flow and the carbon cycle in living systems

Learning Objective 6.1: Describe photosynthesis

Learning Objective 6.2: Describe the relationship between matter, energy, and entropy in an ecosystem

Learning Objective 6.3: Describe how the first two laws of thermodynamics apply to living systems

Learning Objective 6.4: Explain how glucose is broken down and converted into a common energy molecule (ATP) during respiration

Learning Objective 6.5: Identify the structure of ATP

Learning Objective 6.6: Explain the ATP cycle

Learning Objective 6.7: Identify the factors that affect enzyme activity

Learning Objective 6.8: Describe the relationship between photosynthesis and respiration, and the flow of the carbon cycle
Review Questions

The Cell

State and explain the two components of Cell Theory

Identify the varying components and structures (organelles) of the eukaryotic cell and explain their function(s)

Identify the structural and phylogenetic differences between Prokaryotes and Eukaryotes, and explain why cells are small (limited in their ability to get very big).

Be able to identify the differences between viruses and cells, and understand why viruses are not living organisms

Be able to explain the Fluid Mosaic Model of the cell and why it is our best understanding of how cells are structured and perform all the living processes.

What is the ‘Fluid Mosaic’ model of the cell membrane and why is it a good description of what cell membranes are and how they work? What do we mean when we refer to a membrane as being ‘selectively permeable’?

What is diffusion? (i.e., how does it work?), what materials can diffuse across a membrane?, Is it active or passive transport?

What is osmosis?? (i.e., how does it work?), Is it active or passive transport? What is the difference between an isotonic, hypotonic, and hypertonic solution? And what will happen to cells when they are placed in each of these conditions?

What are aquaporins and how do they influence osmosis? Can you provide an example of when and where aquaporins work?

What is a channel protein? What is a gated channel? What is a leak channel? What is a carrier protein? How do cells transport ions through the membrane by facilitated diffusion using either channel proteins or carrier proteins? How do they differ? Are they active or passive transports?

How do pump proteins work against the concentration gradient? Are they active or passive transporters? What is the cellular source of energy that is used to drive coupled transport? Can you provide an example of a pump protein and explain why it is necessary?

How is bulk transport through the membrane accomplished by endocytosis and exocytosis? How does phagocytosis differ from pinocytosis? What is receptor-mediated endocytosis? What is an example of a material that is transported by either endocytosis or exocytosis?

What is the evolutionary origin of mitochondria and chloroplasts as unique organelles that have two membranes and their own DNA?

Make sure you are able to define and use the vocabulary terms that are found in the Module 5 Vocabulary Quizlet.

Energy and Enzymes

What is metabolism?

What is a metabolic pathway?

How does a catabolic pathway differ from an anabolic pathway? How do we define energy?

How does potential energy differ from kinetic energy?

What different forms can energy take?

Can you explain how coupled reactions work as energy flows through a system?

Can you define the first and second law of thermodynamics?

Why does life seem to be an apparent paradox that violates the second law of thermodynamics?

Why does life NOT actually violate the second law of thermodynamics?

What is entropy?

What role does entropy play in the flow of energy through systems?

What is an exergonic reaction?

What is an endergonic reaction?

Can you describe how ATP couples endergonic and exergonic chemical reactions?

What is ‘free energy’ (ΔG)?

How do we calculate ΔG?

Make sure you are able to define and use the vocabulary terms that are found in the Module 6 Vocabulary Quizlet.

The Carbon Cycle

What is the overall significance (or “purpose”) of cellular respiration?

Where does cellular respiration take place in the cell?

Can you explain the difference between aerobic respiration, anaerobic respiration, and fermentation?

What are the byproducts of each of these pathways?

What is an oxidation-reduction (redox) reaction?

Can you distinguish between a molecule that has been oxidized and one that has been reduced?

Can you distinguish the difference between an oxidizing agent and a reducing agent?

Can you describe how molecules such as NAD+ participate in (and transfer energy in) redox reactions. What is an electron transport chain?

Can you summarize the reactions of glycolysis, oxidation of pyruvate (to Acetyl Co-A), the citric acid cycle, and the electron transport chain (oxidative phosphorylation)? In other words, can you describe their specific location within the cell, their net reactants, and net products?

What is substrate-level phosphorylation of ADP to form ATP?

How does this differ from oxidative phosphorylation?

Where do each of these types of ATP formation take place within a cell during cellular respiration?

What role do NADH and FADH play in the electron transport chain and the chemiosmotic phosphorylation of ATP’s?

What is the net yield of ATP per glucose when broken down by a eukaryotic cell aerobically? What is the net yield per glucose when broken down anaerobically (by glycolysis alone)?

What is the overall “purpose” of photosynthesis?

Where do the reactions of photosynthesis take place?

How are pigment proteins involved in the process?

What role does the light spectrum play in the process?

What is accomplished by the light reactions of photosynthesis (products in, products out)?

What is accomplished by the Calvin cycle of photosynthesis (products in, products out)?

Why does almost all life depend on this process?

In the light reactions, what role do the two photosystems play?

What is the advantage to having two photosystems?

How do the photosystems differ in how they work and what products they produce?

Can you summarize the cyclical set of reactions in the Calvin cycle in C3 (normal) photosynthesis?

Where (specifically) do these reactions take place?

What is the name of the carbon-fixing enzyme of the Calvin cycle?

What is photorespiration and why does it occur?

How does photorespiration reduce the efficiency of photosynthesis in C3 plants?

How is the carbon-fixing pathway that is found in C4 and CAM plants different from that found in C3 plants? How does the C4 pathway differ from CAM?

How do these adaptations help plants reduce photorespiration?

Make sure you are able to define and use the vocabulary terms that are found in the Module 7 Vocabulary Quizlet.

The Life Cycle of the Cell

How is the DNA of a eukaryotic cell organized?

What are chromosomes and chromatin?

Be able to list and describe the portions of the cell cycle of a eukaryotic cell.

What events occur in G1, S, and G2?

What occurs during M phase?

Be able to list the stages of mitosis.

What events characterize each of these stages?

Describe cytokinesis (in animal cells) by the formation of a cleavage furrow. Be able to describe cytokinesis (in plant cells) by the formation of a cell plate.

Describe how a bacterial cell divides by binary fission.

How is the cell cycle of a eukaryotic cell regulated? What is a checkpoint? Where are checkpoints located in the cell cycle?

Make sure you are able to define and use the vocabulary terms that are found in the Module 8 Vocabulary Quizlet.