Cell Structures Flashcards
Cell surface membrane
What is it made of?
What does it do?
What does it contain?
Made of mainly lipids and proteins
Partially permeable which regulates the movement of substances
Contain receptor molecules which allow it to respond to chemicals like hormones
Nucleus
What is it do? What does it contain? What does it produce? What does the nucleolus manufacture? What controls the entrance of substance?
Controls cell activities
Contains genetic material as DNA or chromosomes made from (protein bound linear DNA) which is loosely coiled and 1 or more nucleolus.
Produces mRNA and tRNA
Manufactured ribosomal DNA and ribosomes
Nuclear envelope controls entry and exit which also has small holes - nuclear pores.
Mitochondria
Is the mitochondria membrane bound?
What happens to the inner membrane?
What does the interior solution contain?
What is the primary function of the mitochondria?
The organelle is surrounded by 2 membranes - called an envelope/ double membrane with an oval shape.
Inner membrane is folded to form projections called cristae (increased SA) which project into the interior solution - the matrix.
Matrix contains: proteins, lipids, ribosomes, DNA and enzymes involved in aerobic respiration.
Involved in later stages of aerobic respiration and in the production of ATP.
Chloroplast
Is the chloroplast membrane bound?
What is it’s structure and where is it found?
What do chloroplasts contain, and what do they form?
What is the primary function of a chloroplast and where does it occur?
Yes surrounded by a double membrane/ envelope.
Chloroplasts have a small flattened structure and are found in plant and algal cells.
Chloroplasts contain flattened sacs of membrane (thylakoid membrane) which stack to form grana, linked by thin flat structures called lamellae.
Site of photosynthesis which occurs in the grana or stroma, a thick fluid.
Golgi Apparatus
What is a Golgi Apparatus?
How are they formed?
How does the Golgi transport substances around the cell?
What is the function of the Golgi Apparatus?
The Golgi Apparatus is a group of fluid-filled, membrane-bound flattened sacs called - cisternae.
Formed from vesicles which bud off the rough ER.
The ends break down and form vesicles to transport the substances in.
Molecules are collected particularly lipids and proteins and sorted, processed and modified and then packaged for transport.
Lysosomes
What is the shape of the organelle?
What are lysosomes a type of?
What do lysosomes contain?
What is the function of lysosomes?
Lysosomes are a round organelle surrounded by a membrane.
Lysosomes are a type of Golgi Vesicles.
Lysosomes contain hydrolytic (digestive) enzymes: proteases, lipases, and lysozymes.
Lysosomes digest old cell organelles after they die and release enzymes to the outside of the cell. Hydrolyse material infested by phagocytic cells.
Ribosomes
Where can they be found?
What are they made of?
What shape do they have?
What is their function?
They can be found free in the cytoplasm or attached to the endoplasmic reticulum.
They are made of RNA and proteins.
They have a large and small subunit
Ribosomes are the site of photosynthesis. They build protein chains.
Smooth endoplasmic reticulum
What are the Smooth ER?
What is the function of the smooth ER?
A system of flattened sacs - cisternae.
Folds, processes and lipids.
Rough Endoplasmic Reticulum
What are the Rough ER?
What is the function of the Rough ER?
A system of flattened sacs - cisternae.
Folds, processes and synthesises proteins using its ribosomes.
Cell wall
What is the cell wall made from in a plant, algal, bacteria and fungi cells?
What marks the boundary between adjacent cell walls in plants?
What is the role of the cell wall?
Cell walls are made from:
• Cellulose in plants- a polysaccharide of Beta Glucose.
• Cellulose or glycoproteins in algal cells- or a mixture of both.
• Murein in Bacteria- a type of glycoprotein.
• Chitin in Fungi.
Lamella marks the boundary between adjacent cell walls and cements them together.
Prevents cell from bursting via osmosis and keeps the cell relatively rigid by providing mechanical strength, structure and support while preventing shape change.
Allows water to pass along it contributing to movement of water as it is freely permeable.
Large Central Vacuole
What is the membrane surrounding the vacuole called, what does it control?
What is the vacuole and what does it contain?
What is the function of the Vacuole?
The Vacuole is surrounded by a membrane called a tonoplast.
The Vacuole is a fluid-filled organelle with a weak cell sap solution filled with: mineral salt, sugars, amino acids, oxygen, carbon dioxide and pigment for petals.
The vacuole maintain a pressure to keep the cell turgid and stops the cell from wilting. Also isolated unwanted chemicals.
Cytoplasm
What is the cytoplasm?
What is the function of the cytoplasm?
A jelly-like fluid that fills a cell made from mostly water and salt.
Fills the cell up and is responsible for giving the cell it’s shape, where most reactions happen.
Circular DNA (Bacteria)
What is it presented as?
Is it attached to anything?
Presented as one long coiled up strand.
Unlike a nucleus it is not attached to any histone proteins.
Plasmids
What are plasmids?
Small loops of DNA - separate to the circular DNA, which contain genes for antibiotic resistance.
Plasmids aren’t always present.
Capsule
What is the capsule made of?
What is the function of the capsule?
The capsule is made of secreted slime.
The capsule protects bacteria from attacks by cells of the immune system.
