Flashcards in Cells Deck (45):
What is Cytoplasm
All living material (organelles and Fluid) inside the cell except the nucleus.
What is an Organelle
A small part of the cell, usually enclosed by a membrane, that performs a specialised function. Eg. Mitochondria, Lysosome, Nucleus.
What is the Cell Membrane?
A selectively permeable structure that encloses the cell's contents and regulates the passage of materials between the cell and its environment. Also called the plasma membrane.
What is the Nucleus
In eukaryotic cells (all cells except certain bacteria), the double membrane-bound organelle that contains chromosomal DNA, and thus controls the cell's activities.
What is the nucleoli?
Irregular rounded structures in the nucleus. The are sites of RNA synthesis.
What is the Nuclear Envelope
The double membrane boundary around the nucleus. It contains many pores to allow certain moleclues to pass in and out.
What are Chromosomes?
A rod-like group of genes found in the nucleus of eukaryotic cells. Consists of tightly-coiled DNA and proteins.
What is Chromatin?
A stringy network of DNA and proteins in the nucleus. During mitosis and meiosis, it forms rods called chromosomes.
What is the Endoplasmic Reticulum?
A system of branching membranous channels located in the cytoplasm that serves to transport materials within the cell. Rough E.R. contain ribosomes and are a site of protein synthesis. Smooth E.R. have no ribosomes and are a site of lipid synthesis.
What are Ribosomes?
The protein factory of the cell; they are located on the endoplasmic reticulum or in the cytoplasm. COmposed of RNA and protein.
What is the Mitocondria?
"The powerhouse of the cell."Organelles in eukaryotic cells that carry on cellular respiration.
What is Cristae?
The foldings of the inner membrane of the mitochondria. ATP formation happens here.
What are Lysosomes?
Lysosomes are membrane-bound organelles that contain digestive enzymes.
What are the Golgi Apparatus?
An organelle consisting of stacks of flattened sacs. It modifies and packages substances to be transported around and out of cells.
What is a Vacuole?
A Vacuole is an organelle, common in plants, that stores materials such as food, water or wast products.
Define a Phagocytic Vesicle.
A phagocytic Vesicle is an organelle that forms when the plasma membrane folds in as the cell engulfs large particles from outside the cell during phagocytosis (the intake of substances)
What is a microtubule?
A microtubule is a tubular protein structure involved with chromosome movement during cell division. They osmose the internal structure of cilia and flagella, and provide cell shape.
What is a centrosome?
A centrosome is an animal cell organelle attached to the nucleus that is the site of microtubule production.
What is a Centriole?
A centriole is an animal cell strucutre, contained in the centrosome , made of microtubules; they organise microtubule assembly during mitosis and meiosis.
What is the cytoskeleton?
A network of microtubules and other protein filaments that supports the cell stucture and drives cell movement.
What is cilia?
Short hairlike appendages specialised for motion. They enable some protists to move. They also move material along the outside of a cell or across tissue.
What is Flagella?
A long, whip-like projection that allows certain protozoans and also sperm to move.
What is the cell Wall?
The non-living structure that surrounds the cell membrance in plants, algae, fungi and some bacteia. It protects and supports the cell.
What are chloroplasts?
Chloroplasts are organelles found in plants and photosynthetic protists. It contains chlorophyll that absorbs light energy and converts it to chemical energy.
What is the function of the cell wall?
The function of the cell wall is to protect and support, the cell
What is the function of a chloroplast?
It is the site of photosynthesis.
What are the function of cilia and flagella?
Cilia and Flagella's primary function is movement and locomotion (they work like oars on a boat).
What is the function of the endoplasmic reticulum?
The endoplasmic reticulum is a intra-cellular transport system.
What is the function of the golgi body?
The Golgi body packages and secretes proteins.
What is the function of a lysosome?
The lysosome aid intracellular digestion.
What is the function of the mitochondria?
It is the site of cellular respiration.
What is the function of the nucleus?
The nucleus controls all the cells activities.
What is the function of a ribosome?
It controls the synthesis of protein.
What is the function of a vacuole?
Its role is storage.
What is the function of the cell or plasma membrane?
Regulates transport of substances into and out of the cell.
Which organelles are present in plant cells but not animal cells?
The cell wall and chloroplasts are found in plant cells but not animal cells.
What are pseudopodia?
Pseudopodia means "false feet" they are extensions of the cytoplasm; they are used by amoeba for locomotion and food getting, and by some white blood cells for engulfing foreign particles in phagocytosis.
What are the three basic assertions of the Cell theory?
1. All living things are composed of cells.
2. Cells and cell products are the basic units of structure and function in living things.
3. All cells come from pre-existing cells.
What is a prokaryotic cell?
A cell that does not contain a membrane-bound nucleus or membrane-boud organelles, e.eg. Bacteria.
What is a eukaryotic cell?
A cell that contains a membrane-bound nucleus and membrane- bound organelles, e.g. animal and plant cells.
What is diffusion?
The movement of a substance from areas of higher concentration to areas of lower concentration.
What is osmosis?
The diffusion of water molecules across a selectivity permeable membrane (as in a cell membrane).
What is selective Permeability
A property of biological membranes that allows some substances (but not others) to pass through.
What is active transport?
Active transport is the movement of a substance across a membrane against its concentration gradient; requires an input of cellular energy, usually in the form of ATP>