Cell Structures Flashcards by Chloe Gottschall

What is a eukaryotic cell

Multicellular organisms with membrane bound organelles

How well did you know this?

Not at all

Perfectly

What is a prokaryotic cell?

A single called organism with no membrane bound organelles

How well did you know this?

Not at all

Perfectly

What does metabolism involve?

Synthesis and break down of molecules

How well did you know this?

Not at all

Perfectly

Where do reactions take place in a cell?

Cytoplasm

How well did you know this?

Not at all

Perfectly

What separates the cytoplasm from the outside environment?

But the cell surface membrane

How well did you know this?

Not at all

Perfectly

Describe membranes

Selectively permeable and control movement of substances in and out of the cell and organelles
Act as a barrier

How well did you know this?

Not at all

Perfectly

Describe the nucleus

Contains genetic information
Directs the synthesis of proteins
Controls metabolic activity- as the proteins are the enzymes necessary for metabolism
Normally biggest organelle

How well did you know this?

Not at all

Perfectly

Describe the structure of the nucleus

Double membrane- nuclear envelope
Nuclear envelope contains nuclear pores.
Dna very large so has to be transcribed by RNA
Contains chromosomes

How well did you know this?

Not at all

Perfectly

What are chromosomes made from and the processes?

Proteins called histones which form chromatin structures. These coil and condense, forming chromosomes

How well did you know this?

Not at all

Perfectly

What is the nucleolus?

Area within the nucleus
Responsible for producing ribosomes
Composed of RNA and proteins

How well did you know this?

Not at all

Perfectly

What is a mitochondria?

Organelles that is the site of the final stages of respiration, where the energy is stored in bonds

How well did you know this?

Not at all

Perfectly

Describe the strict ur a mitochondria?

Double membrane
Inner membrane folded to form cristae and a fluid interior- matrix
Small amount of dna

How well did you know this?

Not at all

Perfectly

What are vesicles?

Membranous sacs that have storage and transport roles
Single membranes, with fluid inside
Used for transporting materials inside cell

How well did you know this?

Not at all

Perfectly

Describe lysosomes

Specialised vesicles that contain hydrolytic proteins.
Responsible for breaking down waste material in cells.
Break down pathogens by phagocytes in immune system

How well did you know this?

Not at all

Perfectly

Describe the cytoskeleton?

Present throughout the cytoplasm of eukaryotes.
Fibres that are necessary for the shape and stability of cell
Organelles held in place by cytoskeleton.

How well did you know this?

Not at all

Perfectly

What does the cytoskeleton consist of?

Microfilaments
Microtubules
Intermediate fibres

How well did you know this?

Not at all

Perfectly

What are micro filaments?

Contractile fibres.
Formed by actin.
Responsible for cell movement and cell contraction in cytokinesis.

How well did you know this?

Not at all

Perfectly

What are micro tubules?

Globular tubular proteins polymerise to form these scaffold like structures
Determine cell shape.
Act as tracks for movement of organelles

How well did you know this?

Not at all

Perfectly

What are intermediate fibres?

Fibres that give mechanical strength.

How well did you know this?

Not at all

Perfectly

What are centrioles?

Components of the cytoskeleton present on eukaryotes

Composed of microtubules

How well did you know this?

Not at all

Perfectly

What happens when two centrioles join together?

Form centrosome which is involved in organisation and assembly of spindle fibres during cell division.
Play a role in the flagella and cilia to position these structures

How well did you know this?

Not at all

Perfectly

Describe the flagella

Used primarily to enable cells motility.
Sensory organelles to detect chemical changes in cells environment
Whip like
Extensions that protrude from some cells

How well did you know this?

Not at all

Perfectly

Describe the cilia

Hair like
Extensions of a protruding cell
Can be mobile or stationary

How well did you know this?

Not at all

Perfectly

Describe stationary cilia

Present on the surface of cells

Important function in sensory organs like the nose

How well did you know this?

Not at all

Perfectly

Describe the mobile cilia?

Beat in a rhythmic manner that creates a current causing fluid to move Present in the trachea to move mucus out of lungs

What does cilium contain?

Two central microtubules surrounded by nine pairs of mictubules 'wheel like' Known as 9+2 arrangement

Why is it important to synthesise proteins?

For internal use and for secretion

What organelles are involved in photosynthesis

Ribosomes Rough ER Golgi apparatus Cytoskeleton

Describe the endoplasmic reticulum?

Network of membranes enclosed in flattened sacs called cisternae Two types of ERP

What are the two types of the endoplasmic reticulum?

Smooth and rough

Describe rough endoplasmic reticulum?

Ribosomes bound to surface and responsible for synthesis and transport of proteins

Describe the smooth endoplasmic reticulum?

Responsible for lip and carbohydrate synthesis

Describe ribosomes

Free floating in the cytoplasm or attached to rough ER Not surrounded by membrane Constructed of RNA molecules in the nucleolus Site of photosynthesis

What contains ribosomes?

Rough ER Mitochondria Chloroplasts Prokaryote cells

Describe Golgi apparatus

Compact structure formed of cisternae and doesn't contain ribosomes Modify and packages them into vesicles

Describe the route of protein synthesis

- begins in nucleus - mRNA codes for a protein- DNA template created - rRNA is transcribed into nucleolus and folds up to make ribosomes - these then attach to the ER, translate mRNA into proteins which are transported by cisternae. - membrane of ER buds off to form vesicles where the packages of proteins formed on ER travel to Golgi apparatus - this then modifies +packages them for specific destinations in or out the cell - some Golgi vesicles are lysosomes and contain enzymes- these break down old organelles, others move elsewhere by exocytosis

How have prokaryotes adapted to their surroundings billions of years ago What are they called

Could survive extreme heat, temperature and salinity Extremophiles

Prokaryotic cell doesn't have a nucleus, what does it have instead? Describe it

Circular DNA | Controls cells activity, contains a chromosome which is coiled to make compact

Describe ribosomes in prokaryotes

Physically smaller | Small ribosomes- 70s

Describe prokaryote cell wall

Made from peptidoglycan | From amino acids and sugars

Describe a flagella in a prokaryote cell

Thinner and no 9+2 arrangement Uses chemiosmosis not ATP Attached to the membrane of bacterium and rotated by a molecular motor

Describe how the prokaryote flagella attaches to the bacterium

By a basal body and rotated by a molecular motor. Basal body attaches the filament compromising the flagellum to the cell surface membrane. A molecular motor causes the hook to rotate giving the filament a whip like movement- propelling it

What are the mesosomes job in the prokaryote cell

Synthesis of proteins

Average diameter of a prokaryote cell

5um

Average diameter of a eukaryote cell

40um

Ribosomes diameter size in prokaryote cell

18nm

Ribosomes diameter in a eukaryote cell

22nm

What is resolution?

The ability to see separate entities in a cell

What is magnification?

How many times larger the image is than the actual Size

Resolution of a light microscope

50nm

Resolution of a TEM

1nm

What can you see using an electron microscope

A 3-d image | Detailed surface

Function of nuclear pores

Allowed molecules to enter and leave the nucleus

Two features that wouldn't be visible using a medium power light microscope

Nuclear pores Mitochondria Ribosomes

Advantage of using staining

Able to separate different structures to identify them | Increases contrast

Role of chloroplasts

Photosynthesis

Why don't single called organisms need specialised cells

Diffusion is enough Large SA:VR Small so doesn't need a large demand

Two processes inside cell that relays on cytoskeleton

Cytokinesis for chromosomes | RNA for proteins

What is an extra cellular protein secreted out the cell

Enzymes

Suggest on stage during secretion of proteins where energy is required

Transporting vesicles across the cell surface

Role of the Golgi apparatus

To package and modify proteins Make lysosomes Recieve proteins from RER

What are plant cells made from

cellulose

Describe a plant cell wall

Made from cellulose Freely permeable so substances can pass into them Gives it its shape Rigid for supporting shape

What are vacuoles

Membrane lined sacs in cytoplasm containing sap. | Large vacuoles are important in holding the structure and its rigidness.

What is the membrane of a vacuole called? | Describe it

Tonoplast | Selectively permeable, small molecules can get through

What are chloroplasts

Organelles that are responsible for photosynthesis in plants.

Where are chloroplasts found

Cells of the green parts of the plant like leaves.

Describe chloroplasts structure

Double membrane Fluid inside- storma Internal network of membranes-thylakoids Contains DNA and ribosomes

How are chlorophyll pigments made

By the thylakoids joining to form granum, which are joined by membranes call lamellae. These grans contain chlorophyll pigment

What is chlorophyll

Allows plant to absorb light | Gives the plant it's pigment