Chapter 3.1: Plant Cells and Tissues UCF

Prokaryotic

cells lack a nucleus

Eukaryotic

cells contain a nucleus

What are cell walls?

rigid boundary of cells

What are organelles?

membrane-bound bodies found within eukaryotic cells

Cells of higher plants generally vary in length between?

10 and 100 micrometers

Smaller cells have a _____ and more efficient cellular communication due to increase in ___________.

smaller, surface to volume ratio

What is a plasma membrane?

the semipermeable outer boundary of the living part of the cell

Plasma membrane regulates?

movement of substances into and out of the cell

What is the plasma membrane made of?

phospholipids arranged in two layers, with proteins interspersed throughout

Cytoplasm consists of

all living cell components

What is the cytoplasm bound by?

plasma membrane

Cytoplasms consists of all cellar components between the plasma membrane and the?

nucleus

Cytosol

fluid within cytoplasm containing organelles

Organelles

membrane-bound structures of various shapes and sizes with specialized functions

DNA is within the _______ in eukaryotes.

nucleus

Nucleus is the ____ ____ of the cell and contains ____.

control center, DNA

The nucleus sends coded messages from?

DNA to be used in other parts of the cell

The nucleus is bound by?

two membranes, which together constitute the nuclear envelope

On the nucleus, structurally ____ ____ occupy up to one third of the total surface area.

complex pores

These structurally complex pores?

Permit only certain kinds of molecules to pass between nucleus and cytoplasm

The nucleus contains fluid _____ in which have?

nucleoli and chromatin strands

Nucleoli is?

Composed primarily of RNA

Chromatin strands are

composed of DNA and proteins and coil and become chromosomes

Ribosomes

consist of two subunits that are composed of RNA and proteins

Ribosomes link?

amino acids to construct complex proteins

Ribosome subunits are assembled in?

nucleolus

Ribosomes may be on:

The outside of the rough ER, or cytoplasm, chloroplasts or other organelles

Ribosomes have no bounding _________.

membranes

What is the main structural component of cell walls?

cellulose

The cell wall also contain a matrix of?

hemicellulose, pectin and glycoproteins

What is hemicellulose?

holds cellulose fibrils together

What is pectin?

gives stiffness (like in fruit jellies)

What are glycoproteins?

Proteins with associated sugars

What is the middle lamella first produced?

when new cell walls are formed

Flexible _______ _____ are laid down on either side of the middle lamella.

primary walls

________ _____ are produced inside primary walls.

secondary walls

How are secondary walls derived?

From primary walls by thickening and inclusion of lignin

What is embedded in lignin for strength?

cellulose microfibers

Fluids and dissolved substances can pass through ______ ____ of adjacent cells via ______.

primary walls, plasmodesmata

What are plasmodesmata?

cytoplasmic strands that extend between cells through minute openings.

What is the endoplasmic reticulum?

a network of flattened sacs and tubes forming through channels throughout the cytoplasm.

What does the ER synthesize?

membranes for other organelles and modifies proteins

What does the ER facilitate?

cellular communication and channeling of materials

Rough ER

ribosomes distributed on outer surface of ER

The Rough ER is associated with?

protein synthesis and storage

Smooth ER

devoid of ribosomes and associated with lipid secretion

What are dictyosomes?

Golgi bodies in animals and they are stacks of flattened discs or vesicles

What do dictyosomes do?

modify carbohydrates, assemble polysaccharides, and collect them in small vesicles.

Vesicles of dictyosomes are?

pinched off from the margins

Contents of dictysomes may include

cell wall polysaccharides, floral nectars and essential oils in herbs.

______ are the most conspicuous plastids.

Chloroplasts

What are chloroplasts bound by?

double membrane

Chloroplasts contain:

Grana made up of thylakoids

What do thylakoid membranes contain?

chlorophyll

Where do the first steps of photosynthesis occur in?

Thylakoid membranes

What is stroma?

matrix of enzymes involved in photosynthesis

A plastid is a

small circular DNA model

Other types of plastids may

synthesize and accumulate carotenoids, be colorless, may synthesis starches or oils

Mitochondria release energy produced from?

cellular respiration

Mitochondria is bound by?

Two membranes

Inward membrane in mitochondria forms numerous folds called?

cristae

What do cristae do?

increase surface area available to enzymes in matrix

Matrix in mitochondria also includes?

DNA and RNA

What are micro bodies?

are small, spherical bodies distributed throughout the cytoplasm that contain specialized enzymes

Microbodies are bound by?

a single membrane

What do peroxisomes do?

serve in photorespiration

What is the purpose of the cytoskeleton?

involved in movement within the cell

The cytoskeleton is a network of?

microtubules and microfilaments

Microtubules control?

addition of cellulose to the cell wall

Microtubules are involved in the movement of?

flagella and cilia

Microtubules are found in ______ in dividing cells.

spindles

Microfilaments role in?

cytoplasmic streaming

In mature cells, _____ percent of the volume may be taken up by _____ ______.

90, central vacuoles

Vacuoles are bounded by?

vacuolar membranes

Vacuoles are filled with?

watery fluid

The watery fluid in vacuoles contains?

dissolved substances, such as salts, sugars and water soluble pigments known as anthocyanins

Functions of vacuoles?

maintenance of cell pressure and pH, storage of numerous cell metabolites and waste products

Plant cells contain?

cell walls, cell plate and plasmodesmata, and plastids and vacuoles

Animal cells contain?

internal and external skeletons, no cell walls, plasma membrane, have no cell plate nor plasmodesmata

How do animal cells divide?

divide by pinching in two

Animal cells do not have?

plastids nor vacuoles