ALS 2304 Spring 2026 Exam 1 Study Guide

A comprehensive set of practice flashcards covering cell biology, endocrine signaling, growth and stress hormones, and tissue organization for the ALS 2304 Spring 2026 Exam 1.

What is the primary energy currency of the mammalian cell, and how is it generated?

The primary energy currency is Adenosine Triphosphate (ATP), generated through processes like glycolysis, the TCA cycle, and the electron transport chain.

Where in the cell does glycolysis occur, and what are its general start and end products?

Glycolysis occurs in the cytoplasm; it starts with glucose and ends with pyruvic acid.

In which part of the cell is pyruvic acid converted into acetyl CoA?

This conversion occurs in the mitochondria.

What is produced during the process of transcription?

Transcription produces messenger RNA (mRNA) from a DNA template.

What is the secretory pathway, and how does it differ from the production of intracellular proteins?

The secretory pathway involves the translation and export of proteins destined for secretion or the membrane via the endoplasmic reticulum and Golgi apparatus, whereas intracellular proteins are typically translated on free ribosomes and remain in the cytoplasm.

What are the primary categories of hormone, and what determines how they are made?

Hormones are categorized by their chemical composition (e.g., peptides, steroids, amines), which determines whether they are synthesized from amino acids or cholesterol and how they are stored and released.

What are the roles of a ligand and an effector in a signaling cascade?

A ligand is a signaling molecule that binds to a receptor, while an effector is a downstream component (like an enzyme) that carries out the cellular response.

Contrast the functions of kinases and phosphatases.

Kinases are enzymes that add phosphate groups to proteins (phosphorylation), while phosphatases are enzymes that remove phosphate groups (dephosphorylation).

What are the two specific downstream pathways activated by G-protein coupled receptors (GPCR) mentioned in the notes?

The adenylate cyclase pathway and the phospholipase C pathway.

From what specific compound are steroid hormones synthesized?

Steroid hormones are synthesized from cholesterol.

What is the difference between positive and negative feedback in the endocrine system?

Negative feedback occurs when the output of a system acts to oppose or reduce the initial stimulus, while positive feedback reinforces or increases the initial stimulus.

Describe the hypophyseal portal system.

It is a specialized system of blood vessels that allows the hypothalamus to send signaling hormones directly to the anterior pituitary.

Which organ is the primary target of growth hormone (GH), and what is produced as a result of GH binding?

The primary target is the liver, which produces and releases Insulin-like Growth Factor-1 (IGF-1).

How do the anterior and posterior pituitary differ regarding hormone production?

The anterior pituitary produces and secretes its own hormones, while the posterior pituitary stores and releases hormones that were produced in the hypothalamus.

Which hormone triggers the production and release of cortisol during the stress response, and where is it produced?

Adrenocorticotropic hormone (ACTH), which is produced in the anterior pituitary.

Which of the thyroid hormones is considered the most metabolically active?

Triiodothyronine ($T_3$) is the most metabolically active thyroid hormone.

List the $6$ levels of body organization in order from least to most complex.

Chemical, cellular, tissue, organ, organ system, and organismal.

What are the $4$ primary tissue types in the body?

Epithelial, connective, muscle, and nervous tissue.

What are the $2$ primary categories of glands, and how do they differ?

Exocrine glands secrete products into ducts, while endocrine glands secrete hormones directly into the bloodstream.

What are the $3$ primary ways epithelial cells are joined together?

Tight junctions, desmosomes, and gap junctions.

What is the defining feature of connective tissue?

The presence of an extensive extracellular matrix (ECM) that separates the cells.

What are the $3$ primary layers of the skin, from most superficial to most deep?

Epidermis, dermis, and hypodermis.

What role does keratin play in the epidermis?

Keratin is a structural protein that provides strength and waterproofing to the skin as epidermal cells migrate toward the surface.

What muscle is responsible for piloerection (hair standing up)?

The arrector pili muscle.

What are the $3$ primary types of hair discussed in class?

Guard hairs, wool hairs (undercoat), and tactile hairs (vibrissae).

What is the constitutive cell of bone?

The osteocyte.

Contrast the roles of osteoblasts and osteoclasts in bone tissue.

Osteoblasts are responsible for bone formation, while osteoclasts are responsible for bone remodeling and resorption.