Notes, summaries, assignments, exams, and problems for Biology

Energy: Capacity for Change

Potential Energy: Stored energy.

Kinetic Energy: Energy from motion.

Conservation of Energy: Energy cannot be created or destroyed.

Heat: A usually random form of energy.

Entropy: A measure of disorder or randomness.

Chemical Energy: Energy stored in chemical bonds, such as food.

ATP Molecule

Draw a molecule of ATP: Adenosine-P-P-P

Metabolism

Metabolism: The total of all chemical reactions in an organism, requiring enzymes.

ATP and Cellular Work

ATP energy helps cells perform three types of work:

1. Chemical: Assists chemical reactions.
2. Transport: Performs transport work.
3. Mechanical: Moves muscle fibers, for example.

Enzyme Assistance

How do enzymes assist in chemical reactions?

1. Enzymes provide an active site specific to a substrate

Finger prick:

Nociceptors in the finger are stimulated by a mechanical stimuli beginning reflex. AP occurs through graded potentials called excitatory post synaptic potentials. As ESPS summate at axon hillock and surpass threshold AP is created. This happens when an influx of sodium depolarizes the cell, while potassium effluxes. At max influx, gates close.

Sodium potassium pump begins another AP. It goes down myelinated nerve which travels to spinal cord.

Chug water

The water increases blood pressure, which affects the systems.

Circulatory System:

Increased water changes the blood and osmotic condition. The main concern is sodium levels in the body. Since the cell is diluted in water, the cell must adjust to this. Swelling occurs in rnc and also

Properties of the Basilar Membrane

The basilar membrane has varying physical properties along its length:

• Base: Thick, stiff, and narrow (ideal for high frequencies).
• Apex: Thin, less stiff, and wide (ideal for low frequencies).

High frequencies do not move fluid effectively, whereas low frequencies do. Therefore, it is more efficient for high frequencies to cross the membrane early (at the base) and for low frequencies to cross later (at the apex).

Evidence for Active Amplification in the Inner Ear

Experiments measuring sound energy input and output provide evidence for active amplification within the inner ear:

1. Sound energy output was observed to be higher than sound energy input, suggesting an active amplification process.

Outer hair cells are likely... Continue reading "Basilar Membrane Properties and Auditory Signal Processing" »

Organisation and Composition of Life

Levels of Organisation

Abiotic (Non-living) Levels

• Atom Level
• Molecule Level
• Macromolecule Level

Biotic (Living) Levels

• Organelle Level: e.g., Mitochondria
• Cellular Level: The fundamental unit of life
• Multicellular Level:
  • Tissue Sublevel
  • Organ Sublevel
  • Organ System Sublevel

Composition of Matter

• Primary Bioelements: Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur, Phosphorus (CHONSP)
• Secondary Bioelements: e.g., Calcium, Sodium
• Trace Bioelements: e.g., Iron, Zinc

The Building Blocks of Life

Cell Characteristics

Structure and Functions

• Cell Membrane: Surrounds, protects, and regulates the transfer of substances.
• Cytoplasm with Organelles: Carries out vital cellular functions.
• Genetic Material: Contains the instructions for life.

Cell

Organs and Organ Systems

Organs

Organs are complex structures composed of various types of tissue. They perform single or similar functions.

Organ Transplant

Organ transplant is the replacement of a damaged organ or tissue. A common problem is rejection.

Organ Systems

• Nutrition:
  • Digestive system: Digests food and absorbs nutrients.
  • Respiratory system: Exchanges O2 and CO2.
  • Circulatory system: Transports substances throughout the body.
  • Excretory system: Removes metabolic waste, such as urine.
• Interaction:
  • Nervous system: Receives stimuli and sends instructions.
  • Endocrine system: Produces hormones.
  • Locomotive system: Enables movement and provides protection.
• Reproduction:
  • Reproductive system: Creates new life.

Health and Illness

Concept of Health

Health is a state... Continue reading "Human Body: Organs, Systems, Health, and Disease" »

Phospholipid molecules form a bilayer - phospholipids are fluid and move laterally

Peripheral proteins are bound to either the inner or outer surface of the membrane

Integral proteins - permeate the surface of the membrane

The membrane is a fluid mosaic of phospholipids and proteins

Proteins can move laterally along membrane

Diffusion is the movement of particles from a region of high concentration to a region of low concentration, and is the result of the random motion of particles.

Facilitated diffusion is similar to simple diffusion, except that it requires channel proteins or carrier proteins, which are specific to the molecules being transported across the plasma membrane from high concentration to low concentration.

Osmosis is the passive movement... Continue reading "Cell Membrane Structure and Function" »

Fibra:Fiber is a complex carbohydrate of plant origin. Humans
cannot digest fiber or use it as a source of energy or
matter, but it is nonetheless essential for the functioning
of the digestive system.

Nutrients:Organic nutrients: are complex molecules produced by

Inorganic nutrients: are simple molecules that can be
found in living organisms, but have not been produced by
them. These nutrients are essential to your body but do
not supply any energy.
○ Minerals (such as calcium and sodium)
○ Water
○ Oxygen

Vitamins:Vitamins are organic components that the body either
cannot produce or produces only in insufficient
quantities.
● These must be obtained from food.
● All vitamins are needed in small quantities and they are
essential for regulating many... Continue reading "Where is cellobiose found in living organisms" »

Homeostasis and Environmental Response

All living things interact with their environment, including their surroundings and other organisms.

The environment is constantly changing. To survive and reproduce, living organisms must detect these changes and respond appropriately.

Responding to Stimuli

1. A stimulus is detected by receptors (structures or organs).
2. The stimulus is relayed to coordination systems, which interpret the signal and produce a response.
3. The organism responds using effectors (organs or structures).

Maintaining Internal Balance

To survive, living organisms must regulate their internal conditions.

Examples of internal conditions include temperature, water content, and concentrations of mineral salts and glucose in the blood.

Changes in... Continue reading "Homeostasis and Stimuli in Living Organisms" »

Heart Anatomy and Function

Chambers and Valves

The heart is a muscular, hollow organ divided into four chambers:

• Upper Chambers (Atria): Left atrium and right atrium.
• Lower Chambers (Ventricles): Left ventricle and right ventricle.

Between the atrium and ventricle, the atrioventricular valve allows blood flow from the atrium to the ventricle but prevents backflow. The valve between the left atrium and ventricle is bicuspid, while the valve between the right atrium and ventricle is tricuspid.

Blood Circulation

Cardiac Cycle

• Atrial Systole: Atria contract, pumping blood into the ventricles through open atrioventricular valves.
• Ventricular Systole: Ventricles contract, sigmoid valves open, and blood flows into the pulmonary artery and aorta. Atrioventricular

NO BANK/FIB-MULTI Panceras

Endocrine Functions § Pancreatic islets § Secrete hormones insulin and glucagon into blood Exocrine functions § Secretes pancreatic juice into duodenum § Alkaline fluid introduced with enzymes neutralizes chyme from stomach Pancreatic Juice

• Water, bicarbonate solution, enzymes
• Bicarbonate solution: neutralizes gastric HCL & shift pH of duodenum to 8
• Enzymes: § Pancreatic amylase: digests salts § Trypsinogen - digests proteins § Lipase - digests triglycerides

Agriculture:

Deliberate land modification through plant cultivation and raising animals for food or profit Dominant economic activity Requires physical and demographic contributions in regions

Hemoglobin:

Globin combined with 4 iron atoms • 280 million molecules... Continue reading "Endocrine Functions of the Pancreas and Other Organ Systems" »