biology ch 5

Do not focus on memorization. Focus on understanding the concepts!

  Why do plants need energy?

  What is the molecule that provides cellular energy for these activities?

  What is the equation for photosynthesis?

  Does photosynthesis produce ATP that is used in the cellular activities described in your answer to question 1?

  Where do plants get the ATP for cellular activities?

  What is the equation for aerobic respiration?

  Reflect on your answers to questions 1–6 and explain why the statement bolded above sounds right, but isn’t.

Global warming, is the progressive increase of earths average temperature that has been occurring over the past century, advanced researcher thjink that this id due to human activities

Global warming is contributing to global climate change, the local changes in average temperature, precipitation, and sea level relative to historical conditions that are occurring in locations all over the planet. Although Earth’s climate does fluctuate over time due to changes in Earth’s orbit and solar output, human-caused (anthropogenic) global warming has dramatically increased the rate of change—so much so that it may be difficult for humans to adjust.

As Earth warms, it is possible that the abundance of C₄ and CAM plants will increase while the number of C₃ plants (Plant that uses the light-independent reactions of photosynthesis to incorporate carbon dioxide into a 3-carbon compound.) declines as a result of the increased burden of photorespiration. However, C₄ plants (Plant that performs reactions incorporating carbon dioxide into a 4-carbon compound that ultimately provides carbon dioxide for the light-independent reactions.) are mostly grasses, whereas most trees are C₃ plants. Because net rates of photosynthesis in grasslands (as measured by grams of carbon dioxide removed from the atmosphere per acre, per year) are 30% to 60% less than rates in forests, the replacement of trees with grasses significantly decreases the rate of removal of carbon dioxide from the atmosphere.

The loss of trees, deforestation, may happen naturally on a warming Earth as C₄ plants outperform C₃ types, but it is already happening at higher than natural rates thanks to human activities. Deforestation occurs when forests are cleared for logging, farming, and ever-expanding human settlements. Deforestation also contributes directly to the increase in carbon dioxide within the atmosphere; current estimates are that up to 25% of the carbon dioxide introduced into the atmosphere originates from the cutting and burning of forests in the tropics alone. Clearly, one effective way to reduce global warming is to reduce deforestation and promote photos

Anthro means humans

Genic means producing

Photo means light

Chloro means green

Chloroplasts are the specialized organelles in plant cells where photosynthesis takes place. Chloroplasts are surrounded by two membranes (Figure 5.9). The inner and outer membranes together are called the chloroplast envelope. The chloroplast envelope encloses a compartment filled with stroma, the thick fluid that houses some of the enzymes of photosynthesis. Suspended in the stroma are disk-like membranous structures called thylakoids, which are typically stacked in piles like pancakes. The large amount of thylakoid membrane inside the chloroplast provides abundant surface area on which several of the reactions of photosynthesis can occur.

Phyll means leaf

Anthropogenic global warming is caused by recent increases in the concentrations of particular gases in the atmosphere, including water vapor, carbon dioxide (CO₂), methane (CH₄), and ozone (O₃). The accumulation of many of these greenhouse gases (Atmospheric gas such as water vapor, carbon dioxide (CO₂), methane (CH₄), and ozone (O₃) that absorb heat and thus contribute to the greenhouse effect.) is a direct result of coal, oil, and natural gas combustion. The most abundant gas emitted by combustion of these fuels is carbon dioxide; for this reason, carbon dioxide is considered the most important greenhouse gas to control.

Greenhouse effects- is the presence of carbon dioxide and the other greenhouses gasses in the atmosphere Despite this name, the phenomenon caused by these gases is not exactly like that of a greenhouse, where panes of glass allow radiation from the sun to penetrate inside and then trap the heat that radiates from warmed-up surfaces. On Earth, the greenhouse effect works like this: Warmth from the sun heats Earth’s surface, which then radiates the heat energy outward. Most of this heat is radiated back into space, but some of the heat warms up the greenhouse gases in the atmosphere and then is re-radiated to Earth’s surface.

The water cycle- is the continuios movement of water on above and below the earcths surface, involves process of evaporation, condensation, precipitation  and infiltration.

Importance of the high capacity of water to absorb and release heat, so interestingly the water has a specific high heat capacity so it can absorb and release a large amount of heat with only a small change in temperasture , it helps moderate earcths climate by regulatiung temp

                              Why is this? Waters ability to abso0rb and release heat helps to stablizide the earcths surface temperature, preventing drastic temperatures changes that could be harmful to living organisms, it also unfluences weather patterns

Heat, is the total amount of energy associated with the movement of atoms and molecules in a subtsnaces

Temperaturfe is a measure of the intensity for ex how fats the molecules in the substaes are moving

More bigger explanauon f water and heat)

The formation of hydrogen bonds between neighboring molecules of water (Chapter 2) makes it more cohesive than other liquids; in other words, water molecules tend to “stick together.” These same hydrogen bonds also make water resistant to temperature change, even when a large amount of heat is added. This phenomenon occurs because when water is heated, the heat energy first must disrupt the hydrogen bonds. Only after enough of the hydrogen bonds have been broken can heat cause individual water molecules to move faster, thus increasing the temperature. When water cools, hydrogen bonds re-form between adjacent molecules, releasing heat into the atmosphere. A body of water can store a large amount of heat from its surroundings while experiencing only a small increase in temperature, and vice versa

Water’s heat-absorbing capacity has important effects on Earth’s climate. The vast amount of water contained in Earth’s oceans and lakes keeps temperatures moderate by absorbing huge amounts of heat radiated by the sun and releasing that heat during less-sunny times, warming the air and preventing large temperature swings.

As the temperature continues to rise, individual water molecules can move fast enough to break free of all hydrogen bonds and rise into the air as water vapor. This is the basis for the water cycle that moves water from land, oceans, and lakes to clouds and then back again to Earth’s surfaces (Figure 5.3). As the amount of heat trapped near Earth’s surface has increased, the water cycle has sped up. The intensification of the cycle leads to more extremes on both ends of the climate spectrum—in other words, wet places are getting wetter and dry places are getting drier.

Carbond dioxide is one of several greenhouse gases

More carbon dioxide in the atmos[here leads to heat trapped near earths surface

Liquid water when heated turns into vapot

4. Heat is a measure of the total molecular _____________ within a material.

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movement

5. The _____________ bonds in liquid water mean that it is slower to evaporate and can absorb more heat than other liquids, helping to moderate Earth’s climate.

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hydrogen

6. Higher temperatures have _____________ the speed of the water cycle on Earth, increasing precipitation in some regions and leading to drought in others.

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increased

                              Effect on Earth’s temperature and climate The high heat capacity of water helps maintain more consistent temperatures, especially near large bodies of water like oceans and lakes. This moderates extreme heat and cold, which is essential for life on Earth and for maintaining balanced ecosystems.

Understand the flow of Carbon

                              Inorganic carbon à Organic carbon à Inorganic carbon…

  Inorganic Carbon: Carbon in its simplest form, like CO2 in the atmosphere or carbonates in the oceans.

  Organic Carbon: Carbon that is part of living organisms, primarily in the form of carbohydrates, proteins, and fats.

  Cycle: Carbon moves between inorganic and organic forms through processes like photosynthesis (inorganic CO2 to organic carbon in plants) and respiration (organic carbon to inorganic CO2).

What is a producer? An organism that produces its own food, typically through photosynthesis, Plants, algae, and some bacteria are examples of producers. They form the base of food chains by converting light energy into chemical energy.

What is a consumer? An organisms that must east other organisms plants or animals to obtain energy, Animals, fungi, and some bacteria are consumers. They rely on producers or other consumers for food.

Fossil fuels as a store of carbon, Carbon dioxide taken up by plants, algae, and some types of bacteria is converted into carbohydrates using the energy from sunlight. Most living organisms depend on these carbohydrates as a source of cellular energy and rerelease the carbon dioxide into the atmosphere in the process of consuming them. Any unconsumed carbohydrates can become buried in the ground for millennia; the carbon contained there can later be released through volcanic activity or by extraction and combustion by humans. It is the latter activity that is contributing to a buildup of carbon dioxide in the atmosphere.

The stored carbohydrates discussed in the previous paragraph are known as fossil fuels (Figure 5.5). These fuels—petroleum, coal, and natural gas—are “fossils” because they formed from the buried remains of ancient plants and microorganisms. Over a period of millions of years, the carbohydrates in these organisms were transformed by heat and pressure deep in Earth’s crust into highly concentrated energy sources. Humans now tap these energy sources to power our homes, vehicles, and businesses, but as a result of our burning of these fuels, we have released millions of years of stored carbon as carbon dioxide.

Human use of fossil fuels is having a measurable effect; increases in carbon dioxide in the atmosphere are well documented by direct measurements over the past 50 years (Figure 5.6). In addition, scientists can analyze fossil air trapped within ancient ice sheets to determine carbon dioxide over longer time spans. Such measurement is possible because snow falling on an ice sheet surface traps air. As snow accumulates, underlying snow is compressed into ice, and the trapped air becomes tiny ice-encased air bubbles. Thus, these bubbles are fossils—actual samples of the gases in the atmosphere at the time they formed. Cores removed from long-lived ice sheets are analyzed to determine the concentration of carbon dioxide in the atmosphere over time (Figure 5.7). Other gases in the bubbles can provide indirect info

How does the burning of fossil fuels affect the atmospheric levels of inorganic carbon (CO₂)? When fossil fuels are burned for energy, they release carbon dioxide (CO2) into the atmosphere. This increases the concentration of CO2, a greenhouse gas, which contributes to the greenhouse effect and global warming.

How are historic (from thousands of years ago) atmospheric levels of CO₂ measured? They would analyze ice cores taken from glaciers, These cores contain trapped air bubbles, which provide a snapshot of the atmosphere at different times in Earth's history. By studying the concentration of CO2 in these bubbles, scientists can track past CO2 levels.

What is the greenhouse effect?  Is the process by which certain gases greenhouse house gases trap heat in the earths atmosphere , warming the planet. It                `works like a blanket

Greenhouse gases. Which ones are the most important ones?   Carbon dioxide (CO2)

  Methane (CH4)

  Nitrous oxide (N2O)

  Water vapor (H2O)

What would it happen if the atmosphere didn’t have greenhouse gases? Without greenhouse gases, the Earth would be much colder, with an average temperature around -18°C (0°F). This would make Earth inhospitable for most forms of life as we know them.

What would it happen if the atmosphere had an over-abundance of greenhouse gases?

An over-abundance of greenhouse gases leads to excessive heat retention, causing global warming. This could lead to melting ice caps, rising sea levels, more extreme weather events, and disruption of ecosystems.

What is global warming? Global warming refers to the long-term increase in Earth's average surface temperature due to the buildup of greenhouse gases, primarily from human activities like burning fossil fuels and deforestation.

How is global warming and climate change connected? Global warming is a key driver of climate change, which refers to long-term changes in temperature, precipitation, and other atmospheric conditions. While global warming focuses on the increase in temperature, climate change encompasses the broader shifts in weather patterns and ecosystems caused by that warming.

Effect of deforestation on global warming

Deforestation contributes to global warming by:

• Reducing the number of trees that absorb CO2 from the atmosphere.

• Releasing CO2 stored in trees when they are cut down and burned.

Is methane a greenhouse gas? How potent? Yes, methane (CH4) is a greenhouse gas. It is much more potent than CO2 in trapping heat—about 25 times more effective at warming the atmosphere over a 100-year period. However, it has a shorter atmospheric lifespan than CO2.

What is photosynthesis? Photosynthesis is the process by which plants, algae, and some bacteria convert light energy, CO2, and water into glucose (C6H12O6) and oxygen (O2). This process is vital for life on Earth as it provides energy for nearly all living organisms.

Why is photosynthesis so important for life? Photosynthesis is the foundation of most food chains. It produces oxygen, which is essential for respiration in animals, and glucose, which provides energy for plants and the organisms that consume them.

What organisms perform photosynthesis? PLANTS, algae, cyanobacteria , blue green bacteria, primary producers because they create heir own food and serve as the basis for other life forms

In what organelle does photosynthesis happen?

Stroma

Thylakoids

Chlorophyll

Photosynthesis occurs in the chloroplasts of plant cells. Within the chloroplasts:

• Stroma: The fluid-filled space surrounding the thylakoids, where the Calvin cycle occurs.

• Thylakoids: Membrane-bound structures where the light reactions of photosynthesis take place.

• Chlorophyll: A pigment in the thylakoids that absorbs light energy and gives plants their green color.

CO₂ + H₂O + light energyàC₆H₁₂O₆ + O₂

Where does the H₂O come from? It comes from the soil and is absorbed by the plans roots. It them travels through the stem to the leaves where photosynthesis takes place

How does the H₂O get into the plant?

Where does the CO₂ come from?

How does the CO₂ get into the plant?

What is the stoma/stomata?

The stoma (plural stomata) are small pores on the surface of leaves and stems that allow gases (like CO2 and O2) to enter and exit the plant. They also allow water vapor to escape.

Why does photosynthesis take place in 2 steps?

                                             Light reactions: what happens here?

                                             Calvin cycle: what happens here?

(don’t memorize any formulas or reactions)

Photosynthesis occurs in two main steps:

• Light reactions: These occur in the thylakoids and use light energy to produce ATP and NADPH, which are energy carriers.

• Calvin cycle: This takes place in the stroma, where ATP and NADPH are used to convert CO2 into glucose.

Why are plants green? Plants appear green because of chlorophyll, the pigment in the chloroplasts that absorbs light for photosynthesis. Chlorophyll absorbs mostly blue and red light, and reflects green light, which is why we see plants as green.

The water cycle

Importance of the high capacity of water to absorb and release heat

                              Why is this?

                              Effect on Earth’s temperature and climate

Understand the flow of Carbon

                              Inorganic carbon à Organic carbon à Inorganic carbon…

What is a producer?

What is a consumer?

Fossil fuels as a store of carbon

How does the burning of fossil fuels affect the atmospheric levels of inorganic carbon (CO₂)?

How are historic (from thousands of years ago) atmospheric levels of CO₂ measured?

What is the greenhouse effect?

Greenhouse gases. Which ones are the most important ones?

What would it happen if the atmosphere didn’t have greenhouse gases?

What would it happen if the atmosphere had an over-abundance of greenhouse gases?

What is global warming?

How is global warming and climate change connected?

Effect of deforestation on global warming

Is methane a greenhouse gas? How potent?

What is photosynthesis?

Why is photosynthesis so important for life?

What organisms perform photosynthesis?

In what organelle does photosynthesis happen?

Stroma

Thylakoids

Chlorophyll

CO₂ + H₂O + light energyàC₆H₁₂O₆ + O₂

Where does the H₂O come from?

How does the H₂O get into the plant?

Where does the CO₂ come from?

How does the CO₂ get into the plant?

What is the stoma/stomata?

Why does photosynthesis take place in 2 steps?

                                             Light reactions: what happens here?

                                             Calvin cycle: what happens here?

(don’t memorize any formulas or reactions)

Why are plants green?Plants appear green due to the presence of chlorophyll, a pigment that absorbs light primarily in the blue and red wavelengths, while reflecting green light. This selective absorption and reflection of light is crucial for photosynthesis, allowing plants to convert sunlight into chemical energy.

Photosynthesis and Cellular Activities:

• Plants need energy for growth, reproduction, and cellular activities, which is provided by ATP.

• Photosynthesis converts light energy, CO2, and water into glucose and oxygen, occurring in chloroplasts (stroma and thylakoids).

• Equation: CO₂ + H₂O + light energy → C₆H₁₂O₆ + O₂.

Global Warming Factors:

• Global warming is the increase of Earth's average temperature due to human activities and greenhouse gas emissions (CO₂, CH₄, etc.).

• It leads to climate change affecting precipitation, temperature, and ecosystems.

• Deforestation increases CO₂ levels, worsening global warming by releasing stored carbon and reducing carbon absorption capacity.

Greenhouse Effect:

• Greenhouse gases trap heat in the atmosphere, necessary for life. Without them, Earth would be significantly colder.

• An excess of these gases leads to global warming, which results in extreme weather patterns.

Carbon Cycle:

• Carbon moves from inorganic (CO₂) to organic (in living organisms) and back via processes like photosynthesis and respiration.

• Fossil fuels store carbon; their combustion releases CO₂, contributing to atmospheric changes.

Importance of Water:

• Water has a high heat capacity, moderating Earth's climate and stabilizing temperatures essential for life.