BISC104 - Chapter 4 Flash Cards

What is the golgi apparatus?

flattened saccules that receive vesicles from the ER, modifies them, and then sort, process, and repackage them for new destination

What is a channel protein?

forms a tunnel for specific molecules

What is the cell wall?

found on the outside of plant cells, it is made of cellulose and strengthens the cell and maintains the cells shape

How does DNA send messages to ribosomes?

- DNA is organized into genes, which specify a polypeptide - information is relayed to ribosome using messenger RNA (mRNA)

Where are prokaryotic cells found?

bacteria and Archaea

What is the endoplasmic reticulum?

a complicated system of membranous channels and saccules and its physically continuous with the outer membrane of the nuclear envelope

A cell being observed under a microscope has a cell wall, plasma membrane, ribosomes, and chromosomal material that is not found in a nucleus. Based on this information, the cell could be a

bacterial cell

Match the organelle to its function — identify the organelle/function pairing that is mismatched? a) flagella - long, tail-like structure used in motility of some cells b) ribosomes - capable of producing proteins for the cell c) plasma membrane - outermost barrier of a plant cell d) lysosomes - contain digestive enzymes that can digest molecules or cellular components e) nucleus - houses the DNA used for controlling all cell function

c) plasma membrane - outermost barrier of a plant cell

What is the difference between the primary cell walls and the secondary?

primary: - cellulose fibrils and nonocellulose substances - wall stretches when cell is growing secondary: - forms inside of primary cell wall - woody plants - lignin adds strength

What is chromatin?

- it diffuses DNA, protein, and some RNA - prior to cell division, DNA compacts into chromosomes

Which organelle modifies the contents within vesicles and then repackages them for export?

Golgi apparatus

Match organelles to function — which of the following is a correct matching of an organelle and its function? a) Golgi apparatus - protein synthesis b) mitochondrion - cellular respiration c) lysosome - transport d) vacuole - control center e) endoplasmic reticulum - houses DNA

b) mitochondrion - cellular respiration

What organelles does the prokaryotic cell have?

flagella, fimbriae, capsule, cell wall, plasma membrane, cytoplasm, ribosomes and plasmid

Are ribosomes attrached or free?

in eukaryotes: - some are free in cytoplasm - many are attached to the endoplasmic reticulum

What is a receptor protein?

it allows signal molecules to bind, causing a cellular response

What is a cell recognition protein?

it enables our body to distinguish between our own cells and cells of other organisms

What is a junction protein?

it forms junctions between cells and aids in cell-to-cell adhesion and communication

What are chromosomes?

long, thin strings of genetic material made of DNA and proteins

What does the plasma membrane mark the boundary between?

marks the boundary outside and inside of a cell and regulates passage in and out of a cell

What is passive transport?

the movement of materials across the cell membrane without using cellular energy (moving with the concentration gradient; moving high to low concetration)

What are ribosomes?

- carry out protein synthesis in the cytoplasm - consists of two subunits: mix of proteins and ribosomal RNA (rRNA) - they receive mRNA as instructions sequence of amino acids in a polypeptide

What are characteristics of the smooth ER?

- continuous with rough ER - no ribosomes - synthesizes lipids like phospholipids and steroids - function depends on cell - produces testosterone, detoxifies drugs

What does the endomembrane system do?

- helps compartmentalize cells and restricts certain reactions to specific regions - transport vesicles carry molecules from one part of the system to another

What are characteristics of the rough ER?

- its studded with ribosomes - its modifies proteins in lumen - it forms transport vesicles going to the Golgi apparatus

What are vacuoles?

- membranous sacs that are larger than vesicles - they rid a cell of excess water and aid in digestion and storage

What is cellular respiration?

- process that releases energy from food in the presence of oxygen - needs oxygen, produces carbon dioxide

What is the nuclear envelope?

- the double membrane that surrounds the nucleus - nuclear pores permit passage in and out of the nucleus

What is a transport protein?

its involved in passage of molecules through the membrane, sometimes requiring input of energy

What is the endoplasmic reticulum the site of?

site of cellular protein synthesis

What is active transport?

the movement of molecules into or out of a cell with using cellular energy (moving against the concentration gradient; moving low to high concentration)

What is a lysosome?

vesicles that digest molecules or portions of a cell — digestive enzymes

What is the nucleus?

- the control center of the cell - stores genetic information

When was the light microscope invented? and what was its problem?

17th century; it was limited by properties of light

When was the electron microscope invented? how was it different from the light microscope?

1930s; it overcame limitation by using beams of electrons

What is the nucleolus?

a small dense spherical structure in the nucleus of a cell where ribosomal RNA (rRNA) is made

What is an enzymatic protein?

it directly participate in metabolic reactions

What does the cell wall provide support for?

cells in many non-animal cells such as plants, fungi, and protists

What organelles does the eukaryotic cell have?

cilia, plasma membrane, nucleus, smooth ER, nucleolus, mitochondria, lysosome, centrioles, microtubules, and the Golgi apparatus

What organelles make up the endomembrane system?

consists of nuclear envelope, membranes of endoplasmic reticulum, Golgi apparatus, and numerous vesicles

Matching organelle to function — which of the following is a correct match? a) ribosomes - lipid synthesis b) Golgi apparatus - production of cellular ATP c) mitochondria - protein alteration and packaging d) lysosomes - cellular digestion e) smooth endoplasmic reticulum - storage of water

d) lysosomes - cellular digestion

What are mitochondria?

- they are organelles that provide energy for the cell - they break down carbs to produce ATP - inner membrane increases surface area and encloses matrix — mixture of enzymes assist in carb breakdown and reactions permit ATP synthesis

What are chloroplasts?

- use solar energy to synthesize carbs through process of photosynthesis - chloroplasts have their own DNA and ribosomes

Describe the function of a chloroplast?

It converts light energy into chemical energy

There is an antibiotic called streptomycin that inhibits the function of bacterial ribosomes. Consequently, as the bacterial cells die, the person taking the antibiotics gets better. In other words, the antibiotic destroys bacteria by

not allowing them to produce proteins

What is the plasma membrane made of?

phospholipid bilayer with embedded proteins

Where are eukaryotic cells found?

plants, animals, fungi, protists

Both plants and animals need mitochondria to?

produce ATP

What is the flagella?

Long, thin whip-like structure that helps with movement of the cell or fluids past the cell

True or false? A prokaryotic cell does not have a membrane-bound nucleus

True

As a molecule moves through the plasma membrane it passes through?

a hydrophilic layer of phospholipid heads, then a hydrophobic layer of phospholipid tails, and then another hydrophilic layer of phospholipid heads

What is the phospholipid bilayer?

a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends (non polar tails) facing inward and the hydrophilic phosphate ends (polar heads) facing outward