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

Cellular Respiration

Glycolysis

• Enzymes break down a 6-carbon glucose molecule into two 3-carbon pyruvate molecules.
• A small amount of ATP is synthesized through substrate-level phosphorylation, an enzyme-catalyzed reaction transferring a phosphate group from a substrate to ADP.

Oxidative Phosphorylation

• High-energy electrons are delivered to oxygen through a series of electron carriers in the electron transport system.
• The free energy released by electron flow generates an H+ gradient via chemiosmosis.
• ATP synthase utilizes the H+ gradient as the energy source for ATP production.

Reaction Locations

• Glycolysis: Occurs in the cytosol.
• Pyruvate oxidation and citric acid cycle: Take place in the mitochondrial matrix.
• Electron transfer system and ATP synthase

Auto or Self Antigens

Antigens present in one's own cells.

Altered by the action of bacteria, viruses, chemicals, or drugs as a non-self.

Auto antibody

Altered cell (Auto Ag) - elicits the production of Antibody.

Autoimmunity (misnomer, alternative = auto allergy)

Immune response of auto Ab against self Ag.

Humoral or cell-mediated immune response against the constituents of the body's own tissues.

There are more than 80 different kinds of diseases caused by autoimmunity.

Causes of Autoimmune Diseases

Sequestered or Hidden antigens

Ag in the secluded places - are not accessible to the immune system.

Neo antigens

Altered or Modified Antigens – by physical (irradiation), chemical (drugs), or microbial agents (intracellular viruses).

Cessation of Tolerance

It...

Pituitary

• Location: Head 2 lobes - anterior lobe
• Hormone: growth hormone
• Target organ: Whole body, skeleton
• Function: stimulate the growth

• Location: Head 2 lobes - anterior lobe
• Hormone: Thyroid stimulating hormone (TSH)
• Target organ: Thyroid
• Function: stimulate production of thyroid hormones

• Location: Head 2 lobes - anterior lobe
• Hormone: Gonadotropes. Follicle stimulating hormone (FSH) Luteinizing hormone (LH)
• Target organ: Ovaries and testes
• Function: action ovaries and testes

• Location: Head 2 lobes - anterior lobe
• Hormone: Adrenocorticotropic hormone (ACTH)
• Target organ: Adrenal glands
• Function: Stimulate the secretion of adrenal glands

• Location: Head 2 lobes - anterior lobe
• Hormone: Prolactin
• Target organ: breasts
• Function: stimulates breast growth and milk

Gene Pool

The gene pool is the sum of all genetic information carried by all the individuals of a population.

Mutations

Mutations are the ultimate source of all genetic variation, and are the result of random changes in DNA sequences.

Gene Flow

Gene flow is the movement of genes from one population to another. It occurs when individuals migrate from one population to another, thus bringing their genes with them.

Genetic Drift

Genetic drift is a random process where certain alleles are removed from the population by accidental events. It is more likely to affect small populations than larger ones.

Founder Effect

The Founder Effect occurs when a small group of individuals establishes a new population far from existing populations. Because this group is...

The Nervous System

Central Nervous System (CNS)

Brain

Located inside the head, the brain is divided into three regions:

• Cerebrum: Receives and interprets information from the sense organs. Language, memory, learning, and thinking are located here.
• Cerebellum: Plays an important role in motor control and motor learning. It acts in coordination and precision.
• Brain Stem: Joins the brain and spinal cord. It controls involuntary actions.

Spinal Cord

A long, thin tube running inside the backbone, the spinal cord transports information from the brain to the nerves and carries reflexes.

Protection of the CNS

• Hard: Bones protect the CNS. The brain is protected by the skull, and the spinal cord is protected by the backbone.
• Soft: Meninges, a system of membranes

The Excretory System: Function and Components

The **excretory system** is primarily composed of the kidneys, which play a central role in filtering waste from the blood. While other organs like the large intestine remove waste (feces) from the body, the excretory system specifically handles metabolic waste products dissolved in blood.

What is Excretion?

**Excretion** is the biological process of removing waste products of metabolism and other useless materials from an organism. The **kidney** is the key organ in this process, forming the core of the excretory system.

Key Components of the Excretory System

• Kidneys
• Ureters
• Bladder
• Urethra

Blood Filtration in the Kidneys

Toxin-laden blood reaches the kidneys via the **renal artery**. Within the kidneys,...

Blood

Blood is a viscous, red fluid that circulates inside the blood vessels.

An adult usually has about five liters of blood, representing 8% of their body mass. Blood volume varies with age, sex, height, and weight.

Functions of Blood

• Nutrition: Transports nutrients from the digestive system to all body cells.
• Respiration: Carries oxygen from the lungs to the cells and carbon dioxide from the cells to the lungs.
• Excretion: Collects waste products produced by cells and transports them to the excretory system for elimination.
• Defense: Carries the body's defense cells.
• Thermoregulation: Participates in the regulation of body temperature, heating or cooling.

Composition of Blood

Plasma

Plasma is a yellowish liquid, up to 90% water. It contains a variety...

1. Nutrients, Material, and Energy Source

Nutrients are the raw materials from which cells produce their own components. They replace lost components, facilitate growth, and produce new cells. Nutrients are the fuel for cells.

Other nutrients that reach the cells are used as fuel for cellular respiration. Glucose is the nutrient most used by cells as fuel. During cellular respiration, the following events occur:

• Oxygen consumption
• Release of energy usable by cells
• Production of carbon dioxide and water

Lipids and proteins can also be used as fuel to provide nutrients for energy. Cells use this energy to perform their functions.

Our body needs energy-containing nutrients to function; this energy is called chemical energy. Cellular respiration releases...

Polymers

A polymer is a macromolecule composed of long chains of repeating molecular units known as monomers. Polymers are typically organic compounds formed by joining monomers containing carbon, hydrogen, and other elements. The properties of a polymer depend on its monomers and its spatial structure, which can be a linear chain, a ring, or other more complex configurations.

Types of Polymers

• Natural Polymers: Found in nature and formed by living organisms. Examples include proteins and cellulose.
• Artificial Polymers: Derived from chemically modified natural polymers. Celluloid was the first artificial polymer. Other examples include cellulose nitrate, rayon, and vulcanized rubber.
• Synthetic Polymers: Designed and synthesized by humans. Examples