Cells, Tissues and Organs Flashcards
How many different types of cell are there in the human body?
About 200.
What are the 3 principle constituents of a cell (in most cases)?
Nucleus, cell membrane and cytoplasm.
What is the human cell membrane made from and what does it do?
The human cell membrane consists of 2 layers of phospholipids sometimes referred to as a fatty bi-layer. This provides a barrier that ensures water and ions remain in the correct concentrations within the cell (cytoplasm) and outside the cell (interstitial fluid).
What is the function of protein molecules (gates) embedded into the cell membrane?
They transport ions (and other substances) in and out of the cell.
What is the most abundant ion in the intracellular fluid and what is the most abundant ion in the extracellular fluid?
Potassium (K⁺) is the most abundant ion in the intracellular fluid, and Sodium (Na⁺) in the extracellular fluid.
What is meant by the term ‘Active Transport’ ?
Active transport requires the expenditure of chemical energy (adenosine triphosphate / ATP) to transport a substance from an area of low concentration to an area of high concentration.
There are 2 types of bulk transport: Endocytosis and Exocytosis. What is the difference between the two?
Endocytosis refers to the process where the cell membrane surrounds or engulfs something from outside the cell and transports it inside. Exocytosis refers to the process by which waste and other products are exported out of the cell by secretory vesicles.
The nucleus of the cell contains genetic material known as deoxyribonucleic acid (DNA). In simple terms, what is the function of DNA and how is it stored?
DNA is essentially ‘information’ necessary to to control the activity of the cell and produce proteins. It is comprised of paired nucleotides/bases - Adenine (A), Thymine (T), Cytosine (C) and Guanine (G) - that are arranged in sequences of 3 called codons (e.g. CTG) in a unique double-helix configuration.
How many chromosomes does a typical human cell contain?
46 chromosomes (23 pairs).
There are 2 types of cell division: mitosis and meiosis. What is the difference between the two?
During mitosis the cell duplicates all of its contents, including its chromosomes, and splits to form two identical daughter cells (each with 46 chromosomes). Meiosis is sometimes referred to as reductive division since the number of chromosomes is halved, from 46 to 23, and contributes to the production of male and female sex cells (sperm and egg cells).
What is the function of the intracellular organelle mitochondria?
Mitochondria use oxygen and glucose to produce chemical energy for the cell in the form of adenosine triphosphate (ATP).
Complete the following equation: Glucose + O₂ → ATP + ? + ?
Glucose + O₂ → ATP + CO₂ + H ₂O
What do ribosomes manufacture (using messenger RNA and transfer RNA)?
Proteins.
What is the difference between smooth and rough endoplasmic reticulum (ER)?
Rough ER is studded with ribosomes that contribute to the production of proteins and peptide hormones. Smooth ER has no ribosomes and manufactures lipids and steroid hormones.
What is the function of the golgi body?
The golgi body manufactures, store and transports cellular products (e.g. from the ER).
