It is a major part of the transition from the early life forms of the Paleozoic Era to the advanced diversity of the current Cenozoic Era.

The very first flowers (ancestor of roses, magnolias, and hydrangeas) lived during the Cretaceous Period and so did the very last dinosaurs.

The end of the Cretaceous is famously marked by a major extinction that killed off all dinosaurs except birds, many groups of early birds, pterosaurs, marine reptiles, shelled squid-like ammonites, and many other groups.

Climate: Back then Earth was a lot warmer than it is today and there was little or no ice at the North Pole or South Pole. Sea levels fluctuated but were for the most part high. In fact, at times sea levels were 170 meters higher than today.

Continent is once joined togerhter into one supercontinent called pangea.

For the climate, Earth was a lot warmer than it's today and there was little or no ice at the North Pole or South Pole. The exact nature of this catastrophic event is still open to scientific debate.

Evidence suggests an asteroid impact was the main culprit. Volcanic eruptions that caused large-scale climate change may also have been involved, together with more gradual changes to Earth's climate that happened over millions of years.

Whatever the causes, the huge extinction that ended the age of the dinosaur left gaps in ecosystems around the world.

What caused the Great Dying in the Triassic period?

The precise causes of the Great Dying remain unknown. The scientific consensus is that the main cause of extinction was the 

flood basalt volcanic eruptions that created the Siberian Traps,

which released sulfur dioxide and carbon dioxide, resulting in euxinia, elevating global temperatures, and acidifying the oceans.

• This allowed dinosaurs to thrive and take over some of the niches left open due to the extinction of species that had previously held those types of roles in the ecosystem.

-       they help dissipate excess body heat, acting as a cooling mechanism

-       the large surface area aids in detecting faint sounds, allowing the fox to locate prey or potential predators.

2.     Nocturnal Behavior:

-       Fennec foxes are primarily nocturnal, meaning they are active during the cooler nighttime hours.

-       This behavioral adaptation helps them avoid the extreme daytime heat in the desert. By being active at night, they can efficiently search for food without the risk of overheating.

3.     Thick Fur:

-       Despite the desert's hot temperatures during the day, nights can be quite cold.

-       The fennec fox's fur provides insulation, helping it regulate its body temperature in fluctuating conditions. The fur also helps protect the fox from the intense sun during the day.

4.     Kidney Adaptations:

-       Specialized kidneys that enable them to concentrate their urine and extract as much water as possible from the food they eat.

-       This adaptation allows them to survive in arid environments with limited water sources.

5.     Specialized Diet:

-       Fennec foxes have adapted to consume a diet that includes a variety of foods, such as insects, small mammals, and plant matter. This flexibility in diet allows them to take advantage of whatever resources are available in the desert.

The quaternary structure of collagen, particularly its triple helix, provides immense tensile strength and stability. The tight packing of the helices and the extensive hydrogen bonding between them give collagen fibers their strength.

Real-World Application:

• In the beauty and personal care industry, collagen is used in moisturizers and hydrating products to improve skin hydration, elasticity, and overall appearance.

• Collagen is widely used in biomedical applications, including wound dressings, burn treatments, and as a scaffold for tissue engineering. Its biocompatibility ensures that it can be safely integrated into the body, promoting healing and tissue regeneration.

• Collagen's flexibility is utilized in cosmetic and dermatological products, such as dermal fillers and anti-aging creams, which aim to enhance skin elasticity and reduce wrinkles.

Amylase:

The tertiary structure of alpha-amylase is a three-dimensional folding pattern of the protein molecule and folded pattern together by weak and strong chemical bonds that give the protein its particular shape. The tertiary structure of alpha-amylase is essential for its function through folding in a specific way.

Amylase is an enzyme that catalyzes the hydrolysis of starch into sugars, functioning through a highly efficient active site formed by its specific tertiary structure. This enzyme is crucial for digestive health, where it breaks down dietary starches into absorbable sugars in the mouth and small intestine. In the food industry, amylase improves the texture and rise of bread, converts starches into fermentable sugars for brewing, and produces sweeteners like high-fructose corn syrup. Additionally, amylase is used in laundry detergents to remove starch-based stains and in biotechnology for biofuel production and pharmaceuticals. The enzyme's efficiency, specificity, and stability make it invaluable in these diverse applications.

Caspases:

The primary structure of a caspase is an amino-terminal prodomain and a carboxy-terminal protease domain, which contains the key catalytic cysteine residue. Caspases are categorized as initiator or effector caspases, based on their position in apoptotic signaling cascades.

Caspases are protease enzymes crucial for regulating programmed cell death (apoptosis) and inflammation, functioning as dimers or tetramers with highly specific active sites. Their controlled activation through proteolytic cleavage ensures precise regulation of cellular processes. In cancer therapy, reactivating caspases can induce apoptosis in cancer cells, while in neurodegenerative diseases, inhibiting excessive caspase activity can protect neurons from premature death. Inflammatory disorders benefit from targeting caspases to reduce chronic inflammation. Understanding and modulating caspase activity has significant therapeutic potential, making them valuable targets in drug development for treating various diseases where apoptosis and inflammation are dysregulated.

• Alpha-Keratin: secondary structure (helical)

• Beta-Keratin: secondary structure (pleated sheets)

• Function: its fibrous structure helps with a relatively strong structure that can help with resistance to scratches and tearing.

• Keratins are composed of long alpha-helical regions that provide structural stability and resilience to cells.

• Helps with skin barrier, cellular stability, structural support

  
  

Biochemical Catalyst: Salivary Amylase—globular

• Tertiary structure

• Function: In human saliva; initial digestion of starch; sometimes involved in colonization of bacteria

• Facilitates the attachment of starch molecules with the enzyme to begin the process of digestion

  
  

Initiator of cell death: Caspases

• Quaternary structure

• Function: critical in cell regulatory networks controlling cell death and inflammation.

• Activation by Cleavage: Caspases are initially produced as inactive proenzymes (zymogens) which are activated by cleavage at specific sites, ensuring they are only activated when needed to initiate cell death.

• Homodimer Formation: Upon activation, caspases form homodimers, which are essential for their enzymatic activity, allowing them to efficiently process and cleave target proteins involved in apoptosis.

  
  

By: Luna and Arianna

2. biochemical catalysts - Catalase

   • Catalase: type of enzyme

   • Usage: food industry for removing hydrogen peroxide from milk prior to cheese production

   Structure:

   Quaternary Structure: Catalase typically functions as a tetramer, meaning it consists of four subunits. The quaternary structure is the arrangement and interaction of these four polypeptide subunits to form the functional enzyme.

   
   

   Cases:

   Wound Care: Catalase is used in wound dressings and ointments to help reduce hydrogen peroxide levels at wound sites, promoting faster healing and reducing oxidative stress.

   • ex) Catalase, antioxidant enzyme, is essential for restoring this optimal balance. -> catalase catalyses the dismutation of hydrogen peroxide into a molecule of oxygen and water, which is essential for the wound healing process.

   • Therapeutic Treatments: Catalase has potential in treatments for diseases related to oxidative stress, such as Alzheimer's disease, Parkinson's disease, and certain cancers.

     
     

3. Initiator of cell death: P53 gene protein

   • Function: promotes cell cycle arrest to allow DNA repair and/or apoptosis to prevent the propagation of cells with serious DNA damage through the transactivation of its target genes implicated in the induction of cell cycle arrest and/or apoptosis.

   • growth arrest, DNA repair and apoptosis (cell death)

     = commonly mutated gene in human cancers

     -> regulates cell metabolism and oxidative status in response to stress

   • quaternary structure

     • folded core and tetramerization domains

     • flexible molecule composed of four identical protein chains