Introduction to Cell Biology Flashcards
What is a cell?
The smallest functional unit of life capable of carrying out all basic life processes.
State the three main postulates of the cell theory.
1) All organisms are composed of one or more cells.
2) The cell is the basic unit of structure and organization in organisms.
3) Cells arise from pre-existing cells.
Who coined the term “cell” and in what year?
Robert Hooke, in 1665.
What did Anton van Leeuwenhoek discover?
He discovered single-celled organisms, which he called “animalcules.”
What is the main difference between prokaryotic and eukaryotic cells?
Eukaryotic cells have a membrane-bound nucleus and organelles, while prokaryotic cells do not.
Name two examples of prokaryotic organisms.
Bacteria and Archaea.
What is the primary role of the nucleus?
To store and protect the cell’s genetic material (DNA) and control cellular activities.
What is the function of the cell membrane?
To control what enters and exits the cell, acting as a selectively permeable barrier.
What is the function of mitochondria?
To produce energy for the cell through cellular respiration.
What is the function of ribosomes?
To synthesize proteins.
What organelle is unique to plant cells and not found in animal cells?
Chloroplasts (responsible for photosynthesis).
What is the endoplasmic reticulum, and what are its two types?
It’s a network of membranes involved in protein and lipid synthesis. The two types are rough ER (with ribosomes) and smooth ER (without ribosomes).
What is the function of the Golgi apparatus?
To modify, package, and distribute proteins and lipids.
What are lysosomes?
Membrane-bound organelles containing digestive enzymes for breaking down cellular waste and debris.
What is the cytoskeleton?
A network of protein filaments that provides structural support and enables cell movement.
What is the cell wall, and which types of cells have it?
A rigid outer layer that provides support and protection, found in plant cells, fungi, and some prokaryotes, but not in animal cells.
What is the difference between passive and active transport across the cell membrane?
Passive transport doesn’t require energy and moves molecules from high to low concentration, while active transport requires energy and can move molecules against their concentration gradient.
What is the function of vacuoles in plant cells?
To store water, nutrients, and waste products, and help maintain cell shape.
What is the central dogma of molecular biology?
DNA is transcribed into RNA, which is then translated into proteins.
What is the difference between mitosis and meiosis?
Mitosis produces two genetically identical daughter cells, while meiosis produces four genetically diverse haploid cells.
