3.2.1cell Structure Flashcards
(19 cards)
General structure of eukaryotic cells
Cell surface membrane
Mitochondria
Nucleus
Ribosomes
Rough and smooth endoplasmic reticulum (ER)
Golgi apparatus
Lysosomes
Function of cell surface membrane
Selectively permeable- controlled passage of substances in and out of the cell
Molecules/antigens on surface allow cell recognition
Function and structure of ribosomes
Structure:
-made of ribosomal RNA and proteins
-not membrane bound
Function
-site of protein synthesis (translation)
Structure and function of nucleus
Structure:
-nuclear envelope (double membrane that has pores)
-nucleoplasm
-nucleolus
-protein/histone bound linear DNA
Function:
-hold genetic info that codes for polypeptides
-site of DNA replication
-site of transcription
-nucleolus makes ribosomes.
Structure of rER and sER
Both a system of membranes
But ribosomes are on the surface of rER
Fuction of rER
Ribosomes on surface for synthesis of proteins
Proteins are transported in the rER
They are packaged into vesicles for transport to the Golgi apparatus
Function of sER
Synthesis and processes lipids (cholesterol)
Structure of Golgi apparatus and vesicles
Apparatus:
Flattened membrane sacs
Vesicles
Small membrane sacs
Function of Golgi apparatus and vesicles
Apparatus:
-modifies proteins (eg. Adds carbs to produce glycoproteins)
-modifies lipids (eg. Adds carbs to make glycolipids)
-packages proteins into Golgi vesicles
-produces lysosomes
Vesicles:
-transports proteins/lipids
-moves to and fuses with cell surface membrane to release them
Structure and function of lysosomes
Structure:
-a vesicle with a membrane with hydrolytic enzymes
Function:
-release hydrolytic enzymes to break down pathogens or worm out cell components
Structure and function of mitochondria
Structure:
-contains outer membrane
- contains a cristae (inner membrane fold)
-has a matrix contains small (70s) ribosomes and circular DNA
Function:
-site of aerobic respiration
-producing ATP
Structure of chloroplasts in plants
-Double membrane
-stroma, that contain;
Thylakoid membrane
Ribosome (70s)
Circular DNA
Starch granules/lipid droplets
-lamella, thylakoid linking grana
-grana, stacks of thylakoid
Function of chloroplast
Absorbs light for photosynthesis for produce organic substances (carbohydrates)
Function and structure of plant wall
Structure:
-composed of cellulose in plants/algae
-composed of chitin in fungi
Function:
-provides mechanical strength
-prevents cell from bursting (water/osmosis)
Structure and function of vacuole
Structure:
A circular blob contains cell sap
Has a Tonoplast membrane
Function:
-maintains turgor pressure (plants don’t tilt)
- contains cell sap which stores sugars and amino acids
General structure of a prokaryotic cell
Always present:
-cell wall (murein)
-cell surface membrane
-cytoplasm
-small ribosomes
-circular DNA (no association with histones)
Sometimes present:
-capsule
-plasmids
-flagella
Compare differences in structure of eukaryotic and prokaryotic cells
E cells have;
-Membrane bound organelles(ER)
-Nucleus
-Long and linear DNA associated with histones
-larger ribosomes (80s)
-cell wall contains cellulose or chitin
-no plasmids
- are larger
P cells:
-no membrane bound organelles
-no nucleus
-DNA is short and circus
-smaller ribosomes (70s)
-cell wall contains murein
-plasmids can be present
-much smaller size
Why are viruses described as acellular and no living
They are not made of cells -no cell membrane, organelles or cytoplasm
Non-living - no metabolism and can’t independently move/respire/replicate
General structure of a virus
Nucleic acids surrounded by a capsule
Attachment proteins -attaches to host cells
No cytoplasm or ribosome (etc)
Some are surrounded by a lipid envelope (HIV)
