Cells Flashcards
What’s cell theory
All organisms are made of cells, which are the basic units of life and arise from pre-existing cells.
What is the function of the cell membrane?
Separates cell contents from external environment and adjacent cells, controls material transport in/out of cell, helps maintain stability and support the cell
The cell membrane is sensitive to changes in the extracellular environment.
What does the fluid mosaic model describe?
It describes the structure of cell membranes, indicating constant movement of molecules and a variety of different molecules present
‘Fluid’ refers to the movement of molecules, while ‘mosaic’ indicates the diverse components.
What are the main components of the cell membrane?
Phospholipid molecules, cholesterol, and protein molecules
The bilayer arrangement has hydrophilic heads on the outside and hydrophobic tails on the inside.
What percentage of the cell membrane is protein by composition?
2%
Although proteins make up only 2% of the membrane, they constitute 55% of its mass.
What is cytoplasm?
Cell contents between the membrane and nucleus, including fluid
It contains organelles and the cytosol.
What is cytosol?
Liquid component of cytoplasm
Composed of 75-90% water with dissolved salts and carbohydrates.
What is the composition of cytoplasm?
75-90% water, dissolved salts, carbohydrates, suspended proteins, and fats
It serves as the site of most metabolic reactions.
True or False: The cytoplasm helps regulate cell pressure and chemical flow.
True
The cytoplasm plays a crucial role in maintaining cellular functions.
Fill in the blank: The __________ is a protein fiber framework within the cell.
Cytoskeleton
The cytoskeleton provides structural support to the cell.
What are inclusions in the context of cell structure?
Granules or droplets in cytoplasm
These can include various stored substances.
What’s the nucleus?
largest organelle containing DNA and genetic information. Nuclear membrane with pores separates it from cytoplasm. Contains nucleolus for protein manufacturing.
What’s ribosomes and their main job? wya?
small spherical organelles that join amino acids to make proteins. Found free or attached to endoplasmic reticulum.
What’s endoplasmic reticulum (ER)?
parallel membrane system for chemical reactions and molecule transport. Exists as rough ER (with ribosomes) or smooth ER (without ribosomes).
What’s a Golgi body?
membrane stack near nucleus that modifies and packages proteins into vesicles for secretion.
What’s a lysosome?
membrane-bound spheres containing digestive enzymes to break down molecules and worn organelles.
What’s mitochondria?
double-membraned “powerhouses” with folded inner membrane (cristae). Site of cellular respiration providing energy.
What’s cilia and flagella?
hair like structures numerous and short are cilia and long and usually one or two are flagella cilia is found in the nose and in the intestine
