AP Biology class blog for discussing current research in Biology

Tag: ClimateChange

Understanding a Plant’s Stomata to Counteract Affects of Climate Change?!

In mid January, 2023, researchers from the University of California San Diego made an important discovery surrounding photosynthesis, specifically the plants stomata, with climate change implications.

Tomato leaf stomate 1-color

Scientists have understood photosynthesis for many years. As we learned in AP Bio, photosynthesis is the process by which plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of glucose. The process of photosynthesis can be divided into two stages: the light dependent reactions, and the Calvin cycle.

The light-dependent reactions occur in the thylakoid membranes of chloroplasts and involve the conversion of light energy into chemical energy in the form of ATP and NADPH. During these reactions, water molecules are split  into hydrogen ions, electrons, and oxygen gas. The electrons move through a series of electron carriers and ultimately end up on NADP+ to form NADPH. At the same time, hydrogen ions are pumped from the stroma into the thylakoid lumen, creating a concentration gradient that drives the synthesis of ATP through a process called photophosphorylation.

The Calvin cycle, occurs in the stroma of chloroplasts and involve the conversion of carbon dioxide into glucose. During these reactions, carbon dioxide is fixed into organic molecules by the enzyme rubisco. The resulting molecules are then reduced by NADPH and ATP produced during the light-dependent reactions to form glucose. The Calvin cycle also requires a source of hydrogen ions, which are provided by the light-dependent reactions through the production of NADPH.

The researchers at the university of California San Diego, have furthered this understanding by explaining how the stomata is able to sense when to open and close in order to allow carbon dioxide and water to enter and exit the plant. When the stomata is open for carbon dioxide to enter, it exposes the plant to the outside world, and water from the plant is lost, which can end up drying out the plant.

This research is important because as carbon dioxide in the atmosphere increases, it could lead to the stomata of vital plants being left open too much, which would dehydrate the plant.

Fortunately, the research pointed to a specific protein, known as HT1, that was able to activate the enzyme that opens up the stomata in a low CO2 environment. The researchers also found a second protein that blocked the HT1 from keeping the stomata open in environments with higher CO2 concentrations. This second protein that was found is the reason plants will die when the atmosphere has too much CO2, as the stomata wouldn’t be open for long enough to get the necessary resources for photosynthesis.

This can relate to what we learn in AP Bio, in regards to enzymes and proteins. In AP bio, we learned that proteins are large molecules made of amino acids. Enzymes are a type of protein that catalyze chemical reactions. Enzymes also lower the activation energy needed for a reaction to occur. They interact with specific substrates to form enzyme-substrate complexes. The active site of an enzyme undergoes conformational changes, allowing for catalysis. Specific substrates can only bind to a particular enzyme. Enzyme activity can be affected by temperature, pH, and concentration. Enzymes work most effectively within a specific range of those things. Changes outside that range can affect structure and function. Enzymes and proteins play critical roles in many processes. Examples include DNA replication, protein synthesis, and metabolic pathways. Understanding enzyme-substrate interaction is crucial to understanding how the HT1 that activates the enzyme was able to speed up the reactions that caused the stomata to open up.

As Richard Cyr, the program director stated, “Determining how plants control their stomata under changing CO2 levels creates a different kind of opening — one to new avenues of research and possibilities for addressing societal challenges.” Hopefully this research can result in positive steps for the agricultural community as it takes on the challenge that is climate change.


Super-Spreader Plants: The #2 Cause of Biodiversity Loss Worldwide

According to the results of a global research project, conducted by the University of Konstanz and posted in December 2021, “super-invader” plants are a huge problem and greatly reduce biodiversity.

What even is biodiversity? What do the results mean? How does this even happen? Here’s what you need to know about these invasive plants that spread like wildfire.
Large-leaved Lupine (Lupinus polyphyllus). Invasive | Free Photo - rawpixelLarge-leaved Lupine (Lupinus polyphyllus). Invasive species in the wild of Ukraine.

What exactly are ‘invasive’ plants?

Coming from all around the world, invasive plant species cause harm to the environment, the economy, and/or to human health through rapid overpopulation. Most invasive plants come from other continents and countries, but few are native to other regions of the United States.

The extremely harmful side effects of invasive plants

  • a reduction in native biodiversity which adds to climate change, pollution, and more (I encourage you to self-educate on the importance of biodiversity here)
  • alteration of disturbance regimes
  • habitat degradation and loss (the loss of native fish, wildlife and tree species)
  • loss of habitat for dependent and native species (including wildlife)
  • changes in biogeochemical cycling
  • the loss of recreational opportunities and income
  • crop damage and diseases in humans and livestock
Free photo Asian Berry Red Honeysuckle Bush Invasive Plants - Max PixelJapanese honeysuckle

What makes these plants invasive?

Here are some characteristics of invasive plants, through both their properties and how they are distributed over large distances.

  • Can produce large quantities of seed
    • For example, each garlic mustard plant produces hundreds of thousands of seeds–which is a great abundance
  • Seeds are often distributed by birds, wind, or humans which allows them to travel significant distances
  • Many produce chemicals that make it difficult for other plants to grow nearby (ex: garlic mustard plant)
  • Some plants arrive accidentally in air or water cargo
  • Tourism: travelers from one country to another actually commonly spreads things such as insect pests or weed seeds across
  • Produce seeds and leaves that germinate and ‘leaf out’ way early in the spring. As an example, the Norway maple‘s seeds can be 6 inches tall before the plant sprouts, and buckthorns keep their leaves into November, long after native plants have lost theirs.
    • This results in the plant’s leaves being kept late into fall, allowing them to photosynthesize earlier and later than native plants

Looking deeper into this on a molecular level…

File:Photosynthesis.gifphotosynthesis drawing

Looking at the basic science of plants is helpful to understand why this earlier photosynthesis is so important. Plants use sunlight, water, and carbon dioxide to create sugars and oxygen in energy form in the process called photosynthesis. Plants contain chloroplasts that perform this process, which is comprised of light-dependent reactions and the Calvin Cycle (light-independent reactions).

The goal of the light-dependent reactions of photosynthesis is to collect energy from the sun and break down water molecules to produce energy-storing molecules ATP and NADPH. These are then used in the Calvin Cycle to turn carbon dioxide from the air into sugar, providing food for plants.

File:Simple photosynthesis overview.svg - Wikimedia Commons simple photosynthesis diagram

Plants with high photosynthetic rates will grow and reproduce earlier than their native counterparts, often out-competing them and leaving little space for them to thrive. They then can spread really fast due to their other properties listed above.

Why should we care?

Following habitat destruction, invasive species are the second leading cause of biodiversity loss around the world, contributing to climate change and pollution. Forty-two percent of threatened and endangered plants and animals in the United States are directly harmed by the presence of invasive organisms. That’s basically half! Governments around the globe spend billions of dollars each year to control the harm caused by these plants. Yikes.

What can we do?

Here’s what you can do to prevent the super-spread of invasive plants:

  • Learn how to identify these plants and educate your friends about them.
  • Don’t pick, gather, or bring home wildflowers that you can’t identify.
  • Check for weeds and seeds from shoes and clothing after a hike. Also, check your pet’s fur for them! Remove anything that you find before arriving home.
  • Try to keep your car off of weed-infested roads and trails.
  • Be on the lookout for seeds while camping and coming back from vacation!
  • Try to join a plant-removal project! Shown below is the happy result of an invasive species removal project completed by The Southeastern States District Office.

Dr. Mark van Kleunen, Professor of Ecology in the Department of Biology at the University of Konstanz and senior author of the research project’s publication, brings up the most important point: “Unless more effective protective measures are taken to counter the ongoing spread and naturalization of alien plants in the future, they will continue to destroy the uniqueness of our ecosystems — making the world a less diverse place.”

Photosynthesis and Climate

With the recent wild fires in Australia, climate change has been on everyone’s mind. According to the US Energy Information Administration, climate change is in part due to the excessive greenhouse gas emissions, 76% of which come from the burning of fossil fuels.

The greenhouse effect is when heat is trapped near the earths surface by greenhouse gases. There are natural green house gases like carbon dioxide from humans which raise the average temperature of the earth from around 0 degrees to 50, yet since we have continuously been burning more and more carbon dioxide through things like burning fossil fuels, the temperature of the earth keeps rising. Luckily, a group of researchers found a way to try to reduce that number.

A group of researchers tried to imitate photosynthesis by taking energy from the sun to generate chemical fuels, and were successful. Photosynthesis is the process that plants use in order to create food, and ultimately energy from the sun. In order to complete this conversion, H2O must be broken down and the hydrogen atoms must attach to carbon. Then eight electrons and four protons must be added to one molecule of carbon. Even with all these steps, the newly developed copper-iron based catalyst is what makes this process actually work. The carbon and iron “hold onto by their carbon and oxygen atoms“, which allows for enough time for hydrogen  to attach to the carbon.

The process would create a significant change in the amount of greenhouse gas emission if done on a large scale. For this to happen, a artificial photosynthesis panel would have to connect to a source of CO2. While this strategy would be financially costly, the reward for our earth would far surpass any monetary value.

To read more about this research and how it can help our earth, click here.

Climate Change Killing the Environment Part 1000000 – How Ocean Acidification is Damaging Shark Scales

What is Ocean Acidification and How Does it Affect Sea Life?

During Climate Change the amount of carbon dioxide (CO2) in the atmosphere increases which also increases the amount of CO2 in the ocean. This CO2 which dissolves in the ocean combines with water to create carbonic acid. This added acid lowers the pH of the water which therefore acidifies the seawater. When the pH is lowered, the acid harms organisms like coral or other calcium-based structures because the acid starts to break down their calcium. 

Coral Facing the Effects of Ocean Acidification in the Great Barrier Reef

How Does This Affect the Sharks? 

If you look closely at most fish you will see that they have flat scales but Sharks, on the other hand, have scales that resemble teeth and are called denticles. Unlike other fish, Shark denticles cover their entire bodies and influence the way they swim. The denticles on Sharks are also made up of compounds containing calcium which is sensitive to a lower pH. Sadly because of this Sharks like corals will suffer from the effects of Ocean Acidification.  

Shark Denticles under a Microscope

The Study 

The article by the Heinrich-Heine University Dusseldorf focuses on the study which was performed by the research team from two South African research institutions the University of Duisburg-Essen and Heinrich-Heine University. They studied both puffadder shysharks who live on the bottom of the Atlantic Ocean off the coast of Cape Town and ones who lived in the DAFF Research Aquarium in Cape Town. For several weeks the researchers kept one group of sharks in a controlled seawater environment and another group in acidic water. After this time the researchers compared the denticles of these two groups and noticed that on average about 25% of the acidic water shark’s denticles had been damaged while in the controlled group the percentage was less than 10%. The acidic group’s denticles were damaged where it affected their ability to swim. Furthermore, Shark’s teeth are made of a similar compound to their denticles so the acidity also affected their food intake. 

Puffadder Shyshark on the bottom of the ocean floor

How Are Sharks Combatting 

Researchers continued their study and analyzed the blood of the animals in the acidic and normal environments. They discovered that the blood of sharks in the acidic environments had higher concentrations of both CO2 and bicarbonate. Interestingly, as sharks have more bi-carbonate in their blood this prevents the blood from becoming too acidic. This shows that sharks have acid-base regulatory processes for adapting to environmental changes. Although Sharks have a way to combat these changes not all animals have ways to protect themselves. So as more climate changes issues happen it is vital that we as humans are aware of the harm and strive to find ways to reserve its effects. 

The Effects of Climate Change on Plants and Animals

Extreme weather events, such as Hurricane Dorian, have recently become more frequent due to climate change. Changing weather patterns can effect species, but it is unknown what these effects will look like. To solve this problem, Assistant professor of Biology at Washington University in St. Louis Carlos Botero and Thomas Haaland, formerly a graduate student at the Norwegian University of Science and Technology, develop models to predict the effects of changing climate on biological species.

Botero and Haaland used computer simulations to highlight certain factors and traits that put a species at risk for extinction. A key finding was that species that breed a single time in their lifetime evolve as if they were going to experience environmental extreme often while species that breed multiple times in their lifetime evolve as if environmental extremes never happen. The two categories of species are called “conservative” and “care-free” by Botero and Haaland. The former can adapt to frequent, less intense extremes, while the latter can adapt to infrequent, more intense extremes. Because of the rising intensity of natural disasters as a result of climate change, the “care-free” category of animals is less prone to extinction and the “conservative” category of animals is more prone to extinction. Thus, their findings challenge the widely-accepted idea that species with more exposure to environment changes will more easily adapt to climate change.

For example, species in areas with more frequent heat waves are more prone to extinction. Specifically, species that are in these areas with a small geographic distribution are more in danger. This logic can be applied to any kind of environmental extreme, including hurricanes, floods, and wildfires, say Botero and Haaland.

Botero and Haaland also discovered that species with traits that cause them to evolve quicker tend to worsen adaptation to events such as natural disasters. This is partly because of the high mutation rates that accompany faster evolution rates.

Understanding how climate change effects animal species and knowing which species are in the most danger helps aid conservation efforts. People and the governments are able to start by helping protect species that are at the highest level of risk.

Do you think this is enough to offset the effects of climate change? How else can climate change be addressed?


Fish might be shrinking!

To all the seafood lovers, you are being warned here first! The tiny piece of tuna on your plate will soon become even smaller due to climate change. Fish in the ocean will struggle to breathe due to the increasing water temperature, and many species of fish will likely shrink. According to a study published in Global Change Biology, the author predicts a decrease in sizes of the fish by as much as 30 percent. As Nexus Media explains, fish are cold-blooded animals, which means that they cannot regulate their own body temperature. Daniel Pauly, the study’s lead author and a University of British Columbia research initiative, say that due to the increase in ocean temperature, fish will have a higher metabolic rate and have to consume more oxygen. The whole metabolisms in the fish’s body, all the chemical reactions, are accelerated.

Credit:  Attribution license: Taras Kalapun,


So if the fish need to have more oxygen intake, why not just grow bigger gills? In Pauly’s research, he suggests that growing bigger gills won’t help. According to the article, the gills being mostly two-dimensional, just cannot keep up with the three-dimensional growth in the rest of the fish’s body. When a fish grows 100 percent larger, its gill could only grow about 80 percent or less, according to the study. When a gill can no longer supply enough oxygen for a fish’s larger body, the fish will just stop growing larger all together, according to William Cheung, a director of science for the Nippon Foundation. In order to match the decreased supply of oxygen, fish will have to lower their demand, which means that fish of all kinds will shrink as a result of climate change.

There is already evidence to the phenomena of fish shrinking due to climate change, researchers in the North Sea have found that fish stocks like haddock and sole had decreased in body size over the past couple decades, and it is primarily due to climate change since commercial fishing and other factors have been corrected. Furthermore, the entire ecosystem will be affected since the larger fish eat the smaller ones, and a change in body size would alter food web interactions and structure.

To read more about other impacts of climate change on marine species.


Seals in the Antarctic

Today, thanks to modern technology and social networking, there are few parts of the world that remain inaccessible. You can learn things about places you have never been just from looking on your computer screen. However, there are still small parts of the world unexplored and untouched by humans. Antarctica is one of those places sheltered from humans by impossible weather and environment conditions.  “In fact, About 98% of Antarctica is covered by ice that averages at least 1 mile (1.6 km) in thickness” and the average temperature of the continent is -49 degrees celsius.

Explorers and scientists have attempted to learn what they can about the frozen continent but time spent there is limited. Even more seemingly impossible to reach is the Antarctic Ocean Floor. It is tough to study the “extreme Antarctic environment, where observations are very rare and ships could not go”.  To fix this gap of knowledge, scientists attached sensors to the heads of elephant seals. These seals are adapted to the freezing conditions so they can survive in the Arctic ocean with a temperature average of .5 degree celsius.

Southern Elephant Seal image taken from WikimediaCommons


Thanks to the elephant seals, “scientists better understand how the ocean’s coldest, deepest waters are formed, providing vital clues to understanding its role in the world’s climate”. The seals allowed greater insight to the Antarctic bottom water-

“a layer of water near the ocean floor that has a significant impact on the movement of the world’s oceans”. These areas were previously known of but no real data had been obtained. The seals went to areas of the coast line where “no boat could ever go”.

Studies have shown 50 year long trends in these deep water changes. Scientists hope the new data obtained through the seals will help to further uncover these trends that affect global climate change.

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