Gap Finder - Cell Basics

Glucose is nonpolar. T/F

False! Glucose is polar and hydrophilic. It would require a transport protein to help cross the plasma membrane (PM).

Chromosomes

condensed threads of genetic material formed from chromatin as a cell prepares to divide

During protein synthesis, where does translation occur?

Ribosome

Unicellular

made of a single cell

Golgi Apparatus (Golgi Complex)

"Fed-Ex or Shipping Department" - Processes products made by the ER, packages them in membrane and releases them in vesicles for movement across cytoplasm or for exocytosis

identifier proteins

(glycoproteins) Identify cells as self or foreign: ex. Recognize pathogens so an immune reaction can occur

Phospholipid bilayer - which part is formed by a phosphate group?

the head

DNA played a role in the crucial first portion of protein synthesis, ____.

transcription

Which of the following molecules will not be able to easily pass directly through the phospholipid portion of the cell membrane? - Carbon dioxide - Polar molecules - Nonpolar molecules - Oxygen

Polar molecules

Cytoplasm (2)

- A jellylike fluid inside the cell in which the organelles (functional parts) are suspended - Cytosol is the liquid of the cytoplasm

3 main components of a eukaryotic cell

- cell membrane - nucleus - cytoplasm

Lysosomes (2)

- cell's digestive system - digestive enzymes break down damaged organelles or solid particles that have entered the cell

In summary, the cell membrane: (5)

- is ever-changing (fluid mosaic model) - is responsive to cell needs - regulates entry/exit from cell - maintains cell position - communicates w/ other cells

Centrosome

- made of 2 centrioles (direct the movement of chromosomes during division)

Rough Endoplasmic Reticulum (Rough ER)

- membrane network studded with ribosomes for protein synthesis

Mitochondria (2)

- powerhouse of the cell :) - produce most of the cell's ATP

Ribosomes (3)

- site of protein synthesis - found in nucleolus within nucleus - can be free in the cytoplasm OR attached to the endoplasmic reticulum

prokaryotic cell (2)

- type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles. - prokaryotic DNA is in the Nucleoid

Steps of Transcription (3)

1. DNA unzips and the BOTTOM strand is exposed 2. RNA nucleotides attach to the bottom strand, making a mRNA 3. mRNA breaks off and the DNA zips back together

Translation steps (3)

1. mRNA in cytoplasm binds to a ribosome (rRNA) 2. tRNAs anticodons bind to the codons on the mRNA sequence 3. the amino acids on the RNA bind to each other to form a long chain, or protein

Glycocalyx

A superficial carbohydrate coat covering the cell surface that plays a role in cell recognition

Which of the following best describes the cytoskeleton? - An internal framework made of protein microfilaments and microtubules - A wall around the cell that helps it hold its shape - Stacked membranous organelles that provide internal support - Microscopic bones that support the cell on the inside

An internal framework made of protein microfilaments and microtubules

During protein (polypeptide) synthesis, which of the following does not participate in the process of translation? - Ribosomes - Messenger RNA - DNA - Transfer RNA

DNA

Human cells are __________________ cells, meaning they have a ___ ___ and numerous ____ made of ____.

Eukaryotic true nucleus organelles membranes

Prokaryotic vs. Eukaryotic

Eukaryotic cells have a TRUE nucleus (membrane-bound structure holding the cell's DNA) and membrane bound organelles. Prokaryotic cells (BACTERIA) are unorganized and don't have a nucleus

Which of the following best describes the major difference between prokaryotic and eukaryotic cells? - Eukaryotic cells store DNA in an area referred to as the nucleoid. - Eukaryotic cells have a membrane enclosed nucleus. - Prokaryotic cells generally use RNA as their genetic material. - Prokaryotic cells have numerous membrane-bound organelles.

Eukaryotic cells have a membrane enclosed nucleus.

Nucleolus

Found inside the nucleus and produces ribosomes

Which of the following is most likely to pass through a transport protein when entering a cell? - small nonpolar molecules - Glucose - Oxygen - Lipid-soluble molecules

Glucose

Pearson explanation on what molecules would likely need a transport protein!

Glucose is a large polar molecule and would not be able to pass through the membrane without the help of a transport protein. Oxygen, lipid-soluble molecules, and small nonpolar molecules can generally pass through the phospholipid bilayer without needing a transport protein.

Cilia (2)

Hairlike projections that extend from the plasma membrane - wavelike movement sweeps substances over the cell surface

Which of the following incorrectly matches the organelle with its function? - The cytoskeleton provides support and attachment for the organelles. - Lysosomes attached to the rough endoplasmic reticulum allow it to make proteins. - A flagellum allows the cell to move. - The nucleolus makes ribosomes.

Lysosomes attached to the rough endoplasmic reticulum allow it to make proteins.

What RNA is the code for translation?

Messenger RNA

Which of the following is not housed within the nucleus? - Genes - Mitochondria - Nucleolus - DNA

Mitochondria

Which of the following organelles is responsible for generating energy for cellular work?

Mitochondria

During protein synthesis, where does transcription occur? - Nucleus - Ribosome - Mitochondria - Lysosome

Nucleus

Pearson explanation on Cell Features!

Prokaryotic cells like bacteria lack internal membranes. Eukaryotic cells have internal membranes and membrane-bound organelles. All cells contain DNA, are filled with cytoplasm, and have an outer cell membrane.

Which type of molecule forms channels through the cell membrane? - Cholesterol - Phospholipid - Carbohydrate - Protein

Protein

Receptor Proteins

Proteins that transmit information in and out of cells. They allow communication between cells (hormones)

fluid mosaic model

The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.

Which of the following best summarizes the role of the cell's nucleus? - The nucleus makes all of the organelles. - The nucleus makes proteins. - The nucleus contains lysosomes that break down cell debris. - The nucleus contains genes that determine what proteins the cell can make.

The nucleus contains genes that determine what proteins the cell can make.

Peripheral Proteins

The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to one surface of the membrane.

Cells' plasma membrane regulates substances moving in/out of the cell. How?

The phospholipid bilayer prevents most free movement across the PM. It forces the use of molecules in the membrane such as transport proteins.

Smooth Endoplasmic Reticulum (Smooth ER)

The portion of the endoplasmic reticulum that does not have ribosomes attached to it. - makes lipids and carbohydrates

Despite the great variation among cells, they all have three things in common. Which of the following is not a feature common to all cells? - They all have internal membranes - They all contain DNA as their genetic material - They all have an outer cell membrane - They're all filled with cytoplasm

They all have internal membranes - Prokaryotic cells don't have membrane-enclosed nucleus OR organelles!!!

Why do red blood cells have no nucleus?

They have no nucleus so they can contain lots of hemoglobin (a red pigment which can carry oxygen)

Pearson explanation on Translation!

Transcription is the process of copying DNA to an RNA molecule. Since DNA is trapped in the nucleus, transcription must logically occur in the nucleus. Lysosomes and mitochondria do not directly participate in protein synthesis. Ribosomes do, but they participate in translation, not transcription.

What RNA reads the code in order to bring the right amino acid to the right place in the ribosome so it can be bonded to the growing protein chain?

Transfer RNA

anchor proteins

attach to other proteins to help maintain cell structure and shape

Carrier Proteins

bind to and transport substances across the PM

Which of the following is a major role of the glycocalyx of the cell membrane? - cell identification - binding hormones - moving polar molecules into the cell - anchoring the cell to adjacent cells

cell identification

What supplies rigidity/structure to the fluid PM?

cholesterol

Cytoskeleton

delicate filaments and tubes that maintain cell shape & form scaffolding within the cells that provides support and attachment/movement for organelles within the cell

Chromatin

diffused strands containing DNA and protein

The nucleus is enclosed by a

double membrane called the Nuclear Envelope (contains nucleoplasm)

Which component of the cell membrane is hydrophobic?

fatty acid tails (nonpolar)

DNA (genes)

instructions for polypeptide (protein) synthesis

What houses the cell's DNA?

nucleus

Where is RNA made?

nucleus

Which of the following makes up the largest part of the cell membrane? - cholesterol - carbohydrate molecules - peripheral proteins - phospholipid molecules

phospholipid molecules

Integral Proteins

proteins that pass completely through the PM (connect extracellular compartment to intracellular)

Channel Proteins

provide corridors that allow a specific molecule or ion to cross the membrane (these substances normally couldn't cross the PM without the channels)

Cytology

study of cells "cyto-" = cell

Phospholipid bilayer - which part makes up the lipid part?

the two fatty acid tails

All of our cells stem from a single cell. What is it?

the zygote

The cell membrane is semipermeable. T/F

true Some things pass through but others do not.

Transfer RNA (tRNA)

type of RNA that carries each amino acid to a ribosome during protein synthesis

Flagellum

whip-like tail used for movement (found on sperm ONLY)

Can the phospholipids of the PM move?

yes! they give the cell a pliable nature