3.2.1 Cell Structure Flashcards
3.2.1.1 Structure of Eukaryotic Cells, 3.2.1.2 Structure of Prokaryotic Cells and of Viruses & 3.2.1.3 Methods of Studying Cells
(Cell Structure & Microscopy) What are stem cells?
Undifferentiated cells - cell cycle
(Cell Structure & Microscopy) What are specialised cells?
Differentiated cells - certain genes on/off
(Cell Structure & Microscopy) What are tissues?
Group of different cells working together to perform a specific function.
(Cell Structure & Microscopy) What is an organ?
Groups of tissues aggregated together to perform a function.
(Cell Structure & Microscopy) What is an organ system?
Organs working together as a single unit to perform a function.
(Cell Structure & Microscopy) Prokaryotic Cells: No ____ nucleus, only a diffuse area of _______ ________ with no nuclear ________.
true
nuclear material
envelope
(Cell Structure & Microscopy) Prokaryotic Cells: DNA is _____ (not associated with ________).
naked
histones
(Cell Structure & Microscopy) Prokaryotic Cells: ________ strands of DNA but no ___________.
Circular
chromosomes
(Cell Structure & Microscopy) Prokaryotic Cells: No ________ _______ organelles.
membrane bounded
(Cell Structure & Microscopy) Prokaryotic Cells: No ____________, only ______________ regions in some bacteria.
Chloroplasts
photosynthetic
(Cell Structure & Microscopy) Prokaryotic Cells: Ribosomes are _______ (__S type)
smaller
70
(Cell Structure & Microscopy) Prokaryotic Cells: No __, _____ _________ and _________.
ER
Golgi apparatus
lysosomes
(Cell Structure & Microscopy) Prokaryotic Cells: Cell wall made of ______.
Murein
(Cell Structure & Microscopy) Eukaryotic Cells: ________ nucleus, with a nuclear ________.
Distinct
envelope
(Cell Structure & Microscopy) Eukaryotic Cells: Chromosomes _______, in which DNA is located.
Present
(Cell Structure & Microscopy) Eukaryotic Cells: Membrane bound organelles are _______.
Present
(Cell Structure & Microscopy) Eukaryotic Cells: ___________ present in ____ and _____.
Chloroplast
plants
algae
(Cell Structure & Microscopy) Eukaryotic Cells: Ribosomes are ______ (__S).
Larger
80
(Cell Structure & Microscopy) Eukaryotic Cells: __, _____ _________ and _________ present.
ER
Golgi apparatus
lysosomes
(Cell Structure & Microscopy) Eukaryotic Cells: Where present cell wall is made mostly of _________ (or chitin in _____)
Cellulose
fungi
(Cell Structure & Microscopy) What additional features may some prokaryotic cells have?
Cell wall made from muerin
External capsule
Plasmids
Flagella
Pili
(Cell Structure & Microscopy) What does the muerin cell wall do?
Protect against osmotic lysis.
(Cell Structure & Microscopy) What does an external capsule do?
Protection and helps bacteria to stick together.
(Cell Structure & Microscopy) What are plasmids?
Small circular pieces of DNA which have additional genes e.g. antibiotic resistance.
(Cell Structure & Microscopy) What is the flagella?
Motile “tail(s)”
(Cell Structure & Microscopy) Describe the structure of the nucleus.
Largest cell organelle, usually spherical and about 10-20 micrometres in diameter.
(Cell Structure & Microscopy) Describe the functions of the nucleus.
- Acts as the control centre of the cell - controls cell’s activities.
- Controls synthesis of proteins
- Contains the organism’s genetic material (in the form of DNA)
- Manufactures ribosomes from ribosomal RNA
(Cell Structure & Microscopy) What are the features of a nucleus? (5)
Nuclear envelope, nuclear pores, nucleoplasm, chromatin, and nucleolus.
(Cell Structure & Microscopy) Describe the nuclear envelope in the nucleus.
A double membrane that surrounds the nucleus.
The outer membrane can connect to the endoplasmic reticulum (rough).
It controls entry and exit of materials in and out of the nucleus.
(Cell Structure & Microscopy) Describe the nuclear pores in the nucleus.
Allows the movement of large molecules out of the nucleus.
Are usually around 3000 pores.
(Cell Structure & Microscopy) Describe the nucleoplasm in the nucleus.
The jelly like material that makes up most of the nucleus.
(Cell Structure & Microscopy) Describe the chromatin in the nucleus.
DNA exists as chromatin in the nucleus, this condenses into chromosomes during cell division.
(Cell Structure & Microscopy) Describe the nucleolus in the nucleus.
A small sphere in the nucleoplasm.
There may be more than one.
(Cell Structure & Microscopy) Describe the structure of mitochondria.
Usually rod shaped and around 1-10 µm long.
(Cell Structure & Microscopy) Describe the functions of mitochondria.
- Site of aerobic respiration
- Produce ATP during respiration
- Cells with a high level of metabolic activity that require a lot of ATP have lots of large mitochondria with many cristae
(Cell Structure & Microscopy) What are the features of mitochondria? (2)
Double membrane and the matrix
(Cell Structure & Microscopy) Describe the double membrane in mitochondria.
Controls the entry and exit of material. In a membrane is highly folded to form cristae (this takes place where respiration takes place, and the folds provide a large surface area for increased respiration).
(Cell Structure & Microscopy) Describe the matrix in mitochondria.
The remainder of the mitochondrion.
It contains protein, lipids, ribosomes, and circular DNA – allowing it to control the production of some of its own proteins.
Many enzymes involved in respiration are found in the matrix.
(Cell Structure & Microscopy) Describe the structure of chloroplasts.
Typically, disc shaped, but very in shape and size.
Contains DNA and ribosomes, so they can easily manufacture some of the proteins needed for photosynthesis.
(Cell Structure & Microscopy) Describe the function of chloroplasts.
Carries out photosynthesis – converts light energy to chemical energy.
(Cell Structure & Microscopy) What are the features of chloroplasts? (5)
Chloroplast envelope, grana, thylakoids, lamella and stroma.
(Cell Structure & Microscopy) Describe the chloroplast envelope in chloroplasts.
A double plasma membrane – highly selective in what it allows to enter and leave the chloroplast.