Cell biology & homeostasis Flashcards
(46 cards)
Define Cytology
Study of individual cells and their structure.
Define Histology
Study of the microscopic structure of tissues.
Define anatomy
Study of the body’s structure and how its parts relate.
Define physiology
Study of the body’s structure and how its parts relate.
Define Pathology
Study of diseases and abnormalities in body structure and function.
Define pathophysiology
Study of how diseases affect body functions.
What does “patho-“ mean
Relating to disease
What is the anatomical position
when the body is facing forwards with feet together flat on the floor, and arms hanging by the sides with the palms facing forwards
In anatomical direction terms, what does the term “superior (cranial) ” mean
Toward the head or upper part of a structure.
Example: The head is superior to the chest.
In anatomical direction terms, what does the term “inferior (caudal)” mean
Toward the lower part of a structure, away from the head.
Example: The stomach is inferior to the lungs.
In anatomical direction terms, what does the term “anterior (ventral)” mean
Toward the front of the body or structure.
In anatomical direction terms, what does the term “medial” mean
Toward the midline of the body.
Example: The nose is medial to the eyes.
what are the imaginary planes?
median/midsagittal, frontal and transverse
what is the frontal plane
The frontal plane, or coronal plane, is a vertical line that divides the body into front and back parts. It helps describe body positions and movements.
what is median plane
The median plane is an imaginary line that splits the body into equal left and right halves. It runs straight down the middle, from head to toe.
what is transverse plane
The transverse plane is a horizontal line that divides the body into top and bottom halves.
What is the structural and functional feature of the nucleus
The nucleus is the cell’s “brain” because it holds DNA, which controls the cell. DNA is made of four bases: A, T, C, and G. Groups of three bases, called codons, code for amino acids, which link together to make proteins. A gene is a set of codons with the instructions to make a protein.
When a protein is needed, a copy of the gene (mRNA) is made. The mRNA leaves the nucleus, and ribosomes in the cytosol read it to make the protein.
Mention transcription and translation
What is the function and structure of SER
The smooth endoplasmic reticulum (sER) is part of the rough ER but doesn’t have ribosomes, so it doesn’t make proteins. Its main jobs are:
- Making fats for cell membranes.
- Producing steroid hormones like estrogen and androgens.
- Storing glucose and fats.
- Detoxifying drugs and toxins.
- Storing and releasing calcium in muscle cells for contractions.
What is the function and structure of cell membrane
The cell membrane, or plasma membrane, is the outer boundary of the cell and its internal organelles. It is made of a phospholipid bilayer, where phospholipids are arranged in two layers. The heads of these molecules face outward toward the watery environments inside and outside the cell, while the tails face inward, away from water.
This structure makes the membrane semi-permeable, meaning it controls what can enter and exit the cell. Small, lipid-soluble molecules can pass through easily, but larger or water-soluble substances cannot because they are blocked by the hydrophobic tails. Instead, protein channels and carriers help regulate the movement of these substances through the membrane.
What is the function and structure of RER
The rough endoplasmic reticulum (rER) is a large network of membranes around the nucleus and connected to the nuclear envelope. It is more developed in cells that produce a lot of secretions. The surface of the rER has ribosomes, which give it a rough look, and these ribosomes help translate mRNA from the nucleus to create polypeptide chains, which are the building blocks of proteins.
These polypeptide chains enter the rER to be folded into their proper shapes, similar to assembling flat-pack furniture. During this folding process, enzymes in the rER add carbohydrates and phospholipids to the proteins, serving as identity markers. The finished proteins are then packaged into vesicles that bud off from the rER and are sent to the Golgi apparatus for further processing.
What is the function and structure of the golgi apparatus
The Golgi apparatus is a flat network of membranes located between the rough endoplasmic reticulum (rER) and the cell membrane, serving as a packaging center for proteins. New proteins are sent from the rER in vesicles that fuse with the Golgi apparatus to release their contents. Inside, enzymes modify the proteins as they move through, packaging them into vesicles based on their specific functions.
These packaged vesicles can be:
- Secretory vesicles: They fuse with the cell membrane to release proteins outside the cell (a process called exocytosis).
- Membrane vesicles: They merge with the cell membrane to add new lipids and proteins, which can change how the cell responds to its environment.
- Lysosomes: These vesicles contain digestive enzymes that stay in the cytosol. They break down old, damaged, or toxic materials within the cell in a protective environment.
what is the function and structure of cytoplasm
The cytoplasm is the fluid-filled area between the cell membrane and the nuclear envelope. It has two main parts: cytosol and organelles.
- Cytosol, also called intracellular fluid, is where many important chemical reactions happen that provide energy, support growth, repair, and reproduction. It contains enzymes that help these reactions, along with nutrients, ions, and waste products.
-
Organelles are specialized structures within the cell that perform specific functions. They are divided into two types:
- Membranous organelles have phospholipid membranes that keep their reactions separate from the cytosol. Examples include the nucleus, rough and smooth endoplasmic reticulum, Golgi apparatus, mitochondria, and lysosomes.
- Non-membranous organelles are in direct contact with the cytosol and include ribosomes, proteasomes, centrioles, and cytoskeleton proteins.
What is the structure and function of centrioles
Centrioles are paired structures made of protein rods called microtubules arranged in a cylinder. They are located near the nucleus and help organize the cytoskeleton, especially during cell division (mitosis). During mitosis, centrioles create a network of spindle fibers that guide DNA into the two new cells.
what is the structure and function of ATP
Mitochondria are called the “powerhouse” of the cell because they produce energy. Their inner membrane is highly folded to increase surface area and is covered in enzymes that help with aerobic cellular respiration. This process uses glucose and oxygen to create energy in the form of adenosine triphosphate (ATP) and produces carbon dioxide and water as byproducts.
The formula is:
Glucose + Oxygen = ATP + Carbon Dioxide + Water
ATP consists of an adenine molecule and three phosphate groups. Energy is stored in the bonds between these phosphate groups and is released when the bonds are broken.
