A2.2.6 - Eukaryotic Cells

eukaryotic cells

cells that contain a true membrane-bound nucleus and membrane-bound organelles

What are three structures that can be found in plant cells but not animal cells?

chloroplasts

large vacuoule

cell wall

What is the form and func. of the nucleus?

• form: double-membrane bound organelle with nucleolus

• function: contains genetic material + guides cell activity

What are the components of the nucleus?

• double membraned nuclear enevlope with nuclear pores

• nucleolus

• chromatin

• nucleoplasm

What are 3 traits of the nuclear envelope?

• contains pores

• continuous with ER

• double-membraned

What is the form and func. of the nucleolus?

• form: dense, spherical structure that contains DNA

• func: produce ribosomes by transcribing and processing ribosomal RNA

What is the form and func. of nuclear pores?

• form: pores within the double-membrane of the nucleus

• func: exit + entry of substances like mRNA

mRNA

messenger RNA

single-stranded copy of a section of DNA that can move in and out of the nucleus

What is the form and func. of the chromatin?

• form: DNA coiled around proteins called histones 

• func: during cell division, dehydrated by enzymes → chromosomes for cell division (only visible during metaphase)

What is the form and func. of the nucleoplasm?

• form: matrix in nucleus

• func: suspends chromatin, enzymes, nucleotides etc.

What is the form and func. of the mitochondria?

• form: double-membraned organells with highly folded inner membrane (cristae)

• function: produce ATP through cellular respiration

What are the components of the mitochondria?

• outer membrane

• inner membrane 

• cristae

• 70s ribosomes

• plasmids

• intermembrane space

• matrix

What is the form and func. of the cristae?

• form: highly folded inner membrane

• func: increase surface area for cellular respiration

What happens in the intermembrane space of mitochondria?

small space → rapid buildup of hydrogen protons buildup → conc. gradient for ATP production

What is the form and func. of chloroplasts?

• form: large, green double-membrane bound organelles with thylakoids containing chlorophyll

• func: collection/ absorption of light energy → chemical energy for protein synthesis

only found in plants and some fungi

What are the components of the chloroplast?

• outer and inner membrane

• thylakoids

• grana

• lamellae

• stroma

• starch granules

• 70s ribosomes and palsmids

What is the form and func. of thylakoids?

• form: hollow, firsbee-shaped discs containing chlorophyll pigment

• func: absorb light energy + place for light-dependent reactions

What is the form and func. of grana?

• form: stacks of ~60 thylakoids, ~30 per cholroplast

• func: huge S.A. for light trapping → maximizes chemical energy for photosynthesis

What is the form and func. of lamellae?

• form: membrane extensions

• func: connect grana

What is the form and func. of the stroma in chloroplasts?

• form: protein-rich matrix containing enzymes and other substrates

• func: traps CO2, facilitates light-dependent reactions

What is the formation process and func. of starch granules in chloroplasts?

• formation: from excess sugars from photosynthesis

• func: energy source when X light

What theory is supported by the presence of 70s ribosomes and plasmids in mitochondria and chloroplasts?

the endsymbiotic theory - they were originally prokaryotic cells

What is the form and func. of the golgi apparatus?

• form: series of stacked, flattened single-membrane cavities (cisternae) with golgi vesicles

• func: modify, sort and package proteins and lipids → transport or secretion (detoxification)

How does the golgi apparatus secrete substances?

it fuses with the cell membrane

What is the form and func. of the golgi vesicles?

• form: bubble-like sacs budding off the golgi apparatus

• func: transport substances around cell

What is the form of vacuoles and vesicles?

• form: single-membrane bound sacs of fluid

• vesicles: small vacuoles

What is a unique physical trait and 2 func.s of vacuoles in plant cells?

• form: large, permanent

• func: 

  • applies “turgor pressure” → maintain cell structure

  • store water and nutrients

What is the form and func. of vesicles in animal cells?

• form: small + temporary, looks like ribosomes

• func: endocytosis (ex. food from outside it absorbed and digested in vesicles)