Unit 2: Cells Flashcards
Name 2 differences between prokaryotes and eukaryotes.
Eukaryotes are larger than prokaryotes.
Eukaryotes contain a nucleus, prokaryotes have free strands of DNA.
Name 3 differences between plant and animal cells.
Plant cells have a permanent vacuole.
Plant cells have chloroplasts.
Plant cells have a cellulose cell wall.
What is the role of the nucleus?
Contains genetic information which controls the activities of the cell.
What does the nuclear envelope do? (Nucleus)
It connects the outer membrane to the Endoplasmic Reticulum.
What do nuclear pores do? (Nucleus)
They allow large molecules to enter the nucleus.
What is the nucleoplasm? (Nucleus)
The cytoplasm contained in the nucleus.
What are the chromatin? (Nucleus)
They are unwound, free chromosomes within the nucleus.
What does the nucleolus do? (Nucleus)
It creates ribosomes and ribonucleic acid (RNA).
What is the role of mitochondria?
Where aerobic respiration occurs.
What is the double membrane? (Mitochondria)
The outer layer controls what goes in and out of the mitochondria, and the inner layer is folded into the cristae.
What is the cristae? (Mitochondria)
An extension of the inner membrane to increase surface area.
What is the matrix? (Mitochondria)
Found between the cristae, where enzymes for respiration are contained.
What is the role of ribosomes?
They create proteins.
What are the subunits of a ribosome?
The large unit and the small unit, both containing RNA and protein.
What are the two types of ribosome?
80S and 70S
What is the role of the Rough Endoplasmic Reticulum?
For protein synthesis. Its’ folds process proteins and offer a pathway for the transport of materials throughout cells.
What is the RER made of?
Sheet-like membranes that spread out throughout the cytoplasm, providing a large surface area for ribosomes to attach to during protein synthesis.
What is the role of lysosomes?
Intracellular digestion of materials.
What is the role of centrioles?
Organisation of the spindle.
What is the role of the golgi apparatus?
It is involved with the modification of proteins. Also creates lysosomes.
What are microtubules and what is their role?
Fine, hollow structures composed of the protein tublulin. They contribute to the cykoskeleton and the centrioles, as well as making up the spindle.
What is the Fluid-Mosaic model?
The phospholipid bilayer has a mosaic pattern between each end of the phospholipid - they were also able to move about, resulting in the name Fluid-Mosaic.
What is the role of the cell wall?
Provides structure for plant cells.
What is the role of the cell surface membrane?
Regulates movement of substances in and out of the cell.
What is the role of microvilli?
Found on cells involved in processes such as absorption.
What is the role of a vescicle?
Transports substances in and out of a cell.
What is the role of a chloroplast?
The site where photosynthesis takes place, contains chlorophyll and absorbs light.
What is the definition of:
Diplococci
Streptococci
Sarcinae
Staphlococci
Pairs
Chains
Packets
Clusters
What are the key features of prokaryotes?
- blue green algae is photosynthetic
- DNA processes singular circular thread of DNA
- plasmids only carry few genes, antibiotic resistance, special metabolic pathways
- shapes = cocci, bacilli, spirilli
Importance of bacteria:
- decomposers in carbon cycle
- nitrogen fixing bacteria in nitrogen cycle
- pathogens (disease)
- gut flora help with digestion
What is viral replication?
A vines cannot reproduce itself, it weest invade a host cell and take over the cell activities, eventually causing destruction of the cell, and killing it.
What is the organisational hierarchy of a cell?
- Biological molecules
- Organelle
- Cell
- Tissue
- Organ
- Organ system
- Organism
Structure and function of the central vacuole.
- Any fluid filled space in a cell with a membrane
- Filled with cell sap (provides osmotic pressure).
- Animal cells may have temporary vacuoles.
- Important in controlling osmosis
- Used as a storage vessel
Structure of chloroplasts
They are large
Contain DNA and ribosomes
Surrounded by an outer membrane.
Membrane with a large sa.
Contain chlorophyll
Cell specialisation
Egg g+ sperm → zygote → mitotic division, day 5-6 turns into stem cells.
Embryonic stem cells are pluripotent.
On day 5-6, all cells are the same. The gene is switched on and will produce a protein and an enzyme to allow the cell to become specialised = gene expression.
Plasmids in prokaryotes notes
- help with antibiotic resistance
- they are molecules peoduced by pathogens that specifically influence a hosts function to allow the pathogen to thrive
- promote bacterial conjugation
What is the cytoplasm (protoplasm in prokaryotes)
- gel-like matrix of warer, enzymes, nutrients, wastes, gases and contains cell structures
-location of growth, metabolism and replication - a bacterias way of storing nutrients in granules
What is cellular scaffolding
- a backbone or skeleton for cells, within the cytoplasm