Cell Biology Flashcards
The cell
basic structural & functional unit of a living organism
Tissue
groups of cells within similar structures that work together to perform a function
Organs
a structure made up of different tissues within an animal that perform a specific function
Organ system
a group of organs & tissues related by function
Cell hierachy
Cell
Tissue
Organs
Organ system
Functions of cells
-Store energy/production of energy
-Aid in reproduction
-Provide support and structure
-Facilitate growth
-Transportation of substances
-Specialised functions eg nervous system
Eukaryotes
-Have a true membrane-bound nucleus and cell organelles
-Contain mitochondria (respiration/energy)
-Cell wall is the outermost layer
-Genetic material is DNA
-Cells divide via mitosis (sexual reproduction)
Mitochondria
-Sac-like membranous organelles
- Where respiration takes place
-Their walls consist of two membranes
-Chemical reactions produce the energy
-Main storehouse for the respiratory enzymes of the cell
-Storehouse for other substances that are needed to store energy from respiration
-Energy from respiration is stored in the form of a chemical compound, ATP(adenosine triphosphate)
Cytoplasm
- Allows substances to be transported across the cell, keeps cell organelles in place
-Fluid-like substances present between the cell membrane and nucleus
-Mainly composed of water
-Contains a net-work of threads and microtubules that help the cell to maintain its shape and form
Ribosomes
-Round-shaped organelles that synthesise protein in the cell
-Builds proteins
-Some present in the cytoplasm where protein is produced and released into the cytoplasm
-The cell uses it for growth & regeneration
The Nucleus
-Spherical/oval shape and is located in the middle of the cell
-Contains DNA, controls the activities of the cell
-Surrounded by a double membrane called the ‘nucleur envelope’
-The nucleur envelope seperates the contents of the nucleus from the cytoplasm. There are tiny pores through which substances pass between the nucleus and the cytoplasm
Smooth endoplasmic reticulum
-A network of membranous canaliculi that extends in all cytoplasm
-lacking ribosomes, helps produce and package lipids and hormones
Golgi apparatus
-A series of flat membrane-bound sacs
-Packages proteins and lipids and transports them across the cell
-The number differ in the cell according to the cell’s secretion activity
-They are specialised for receving the molecules of substances secreted by the endoplasmic reticulum across a group transporting vesicles
Lysosomes
-Small, round, membranous vesicles formed by golgi bodies
-Contains digestive enzymes that breakdown old cell organelles
-They contain a group of digestive enzymes
-The function: is to get rid of warn and senile celld and organelles who no longer nave benefits
-They digest the large molecules of nutrients engulfed by the cell and change them into simpler substances for the cell to benefit from them.
Peroxisomes
-Single membrane-bound vesicles
-Contain several different enzymes, involved in various metabolic pathways
-Involved in the oxidation of fatty acids, a major source of metabolic energy
